Babbitt what is it

Properties of babbitt. Composition, brands, production and use of babbitts

This article is dedicated to the alloy created by the jeweler - we are talking about the American Isaac Babbitt. It was Babbitt, who brought the inventor a prize of 20 thousand in 1841.

dollars from the United States Congress, marked a turning point in his career - the jeweler began to specialize in alloys. Babbitt was already patented in Great Britain in 1844, and in 1847 in the Russian Empire.

You will definitely find out further why the brainchild of a scientist from the USA is valuable in modern times, where it is used, how much it costs and what features it has.

Babbitt - what is it?

In honor of I. Babbitt, an alloy of three metals was named, which is most valuable in the production of bearings - the Babbitt melt is poured onto the walls of the internal steel shaft of the part, along which friction occurs during rotation. The invention of the American scientist can significantly reduce bearing wear.

Babbitt composition contains tin, antimony, lead and copper in different proportions. Since Babbitt metal consists of both soft and hard elements, it is distinguished by its anti-friction properties and wear resistance. Bearings made from it fit tightly to the shafts and are used for a long time.

The duration of proper operation of Babbitt bearings directly depends on the thickness of the layer of this alloy poured onto the steel liner. The thinner it is, the longer the part can be used.

Let us list the main remarkable properties of the alloy:

• antifriction material - resisting friction (reciprocating movements of the “back and forth” type);
• corrosion resistance;
• low hardness (HB 13-32);
• wear resistance;
• high thermal conductivity;
• not too high melting point - 240-340 degrees Celsius;
• increased softening of the alloy at 100 degrees Celsius (HB 9-24);
• increased impact strength.

Advantages and disadvantages of babbitt

Considering the properties of babbitt, we will touch on its key pros and cons. The advantages of the alloy include its anti-friction qualities and excellent wearability to the part. The alloy significantly increases the service life of the bearing and its wear resistance - during operation, microchannels are formed in the babbitt layer, through which the lubricant gets to the part.

One significant disadvantage of babbitts is their low strength compared to other alloys. Because of this, such a layer is limited to a stronger cast iron, steel or bronze body.

Types and grades of alloy

There are three types of babbitt brands, depending on the base metal:

1. Calcium. Although its base is lead, the alloy gets its name from one of its components - it also contains calcium and sodium. These elements distinguish this babbitt at the most inexpensive price and give it increased thermal conductivity and density. But at the same time, such an alloy oxidizes faster, which does not add wear resistance to it. Therefore, calcium babbitt is in most cases used in frame liners of cars, both freight and passenger - there they are most often checked and, if necessary, quickly replaced.
2. Tin. The basis of this babbitt is tin, which is characterized by a high coefficient of friction, high wear resistance and ductility, and increased corrosion resistance. This alloy is approximately twice as strong as its “brothers”. Therefore, this brand of Babbitt is indispensable for bearings that bear the maximum load and play an important role. Their area of ​​application is various low-speed engines. In addition to tin, this alloy contains either cadmium and nickel, or antimony and copper. The only disadvantage of tin babbitt is its highest price among these alloys.
3. Lead. The soft components here are lead and antimony - 87% and 13%, respectively, in this segment. The solid element of the alloy is crystalline antimony (5% of the total volume). This babbitt is not particularly elastic, which is why it is used for the production of bearings that are not particularly loaded. However, it is remarkable in that it perfectly tolerates high-temperature heating of the element. It is worth noting that such babbits are more susceptible to corrosion than others. Their path is diesel engines of tractors and cars.

Lead babbitt grades - B16 (lead is the main element), BS6, BN (lead, tin, nickel, copper, arsenic, cadmium, antimony). They, like tin ones, are produced in accordance with GOST 1320-74. Calcium alloys comply with GOST 1209-90; their varieties are BK2, BKA, BK2TS, BK2SH.

Brands of tin babbitt are B83, B83S (small addition of lead), B88. Variety B83, for example, is 80% tin component, 12% antimony, 6% copper and, on average, 0.1% each of bismuth, lead, iron, arsenic, and aluminum.

And B6 is 88% lead, 0.3% copper, 0.1% iron, a small proportion of zinc and arsenic.

Alloy production

The properties of babbitt directly depend on its components. To produce it, you only need to extract its elements (or process recycled materials), because it itself is a completely man-made alloy. The finished form of babbitt is ingots, pigs weighing no more than 22 kg. To cast them, the material is carefully prepared - cleaned and degreased. When melting, the sprudin, a refractory foam, is removed from the surface of the mass.

Babbitt production ends with the casting of ingots. Each of them is imprinted with the company's trademark, brand and serial number of the heat. Workers at a plant specializing in casting bearings melt ready-made babbitt pig briquettes and pour the melt into the bearing shell.

Babbitt melting

To obtain such alloys, both primary metals—primordial ore—and secondary metals—remelting scrap metal—are used. In addition to the main components listed in the previous paragraphs, cadmium, arsenic, sodium, and tellurium are added to babbits.

Babbitts B16, BN, B88 and others are cast into ingots (ingots), characterized by a strictly defined mass. It is also important that the slightest contamination is not observed on the surface of the ingot - even such a factor can negatively affect the quality of the bearing.

The brand of Babbitt also affects the melting point of the alloy. Thus, the most popular babbit B83 melts at a temperature of +240 degrees Celsius, and tin B83 melts at +340-440 degrees on the same scale.

Specifics of using babbitt

Each type of part requires its own brand of babbitt alloy:

• Connecting rod bearings (joint of the piston and crankshaft) - BM brand. Used for tractors. They require replacement with new ones every thousand kilometers.
• Main bearings use B88 babbitt, created specifically for high speeds and high dynamic loads. Therefore, this brand is successfully used for medium-speed and high-speed diesel engines.
• Bearings for ship water pipelines and compressors - a type of BN, ideal for medium loads and speeds.
• Heavy engineering - the properties of grade B16 babbitt are perfect.

Babbitt cost

Let's consider the cost of this alloy in the Russian Federation. The price directly depends on the properties of babbitt and its brand. Thus, the average price of lead babbit B16 is about 350 thousand rubles/ton. The cost of B83 alloy is about 1.3 million rubles/ton.

If we consider the market for recyclable materials, then 1 kg of babbitt scrap metal can be sold for a maximum price of 500-600 rubles/kg. Basically, such alloys are purchased for their subsequent disposal, because unnecessary bearings can cause irreparable harm to the environment, since cadmium, lead, and antimony are literally poisons for the nature around us.

Babbitt alloys are far from a modern invention. However, they are still relevant in mechanics today, namely in the production of bearings.

This is observed due to the fact that babbits are durable, wear-resistant, quickly and tightly rubbed into the part, ensure noiselessness during friction and, due to their low thermal conductivity, eliminate engine overheating.

In addition, manufacturers offer dozens of different brands of babbitts, each of which corresponds to a specific type of both the bearing and the entire engine of the machine.

Source: https://FB.ru/article/326018/svoystva-babbita-sostav-marki-proizvodstvo-i-primenenie-babbitov

Babbitt - what kind of alloy is it

Babbitt is an anti-friction alloy first produced by jeweler and inventor Isaac Babbitt. It was not used for the production of jewelry, but was widely used in industry. In 1841, Babbitt received a gold medal from the Massachusetts Mechanics Association, and 3 years later, $20,000 from the US Congress for transferring rights to a patent for a unique metal.

Babbitt has a heterogeneous structure based on lead and tin. The composition also includes additional substances that act as alloying additives: copper, antimony, nickel, cadmium, etc. The specific properties of the metal depend on them. For example, copper increases the ability to withstand shock loads. Nickel is responsible for wear resistance. The degree of corrosion resistance of a product depends on cadmium. Antimony increases overall strength.

The combination of substances made it possible to obtain high-quality material for filling bearings. It is applied in a thin layer to the liner by spraying or casting. Combining a plastic base and hard particles, the material ensures fast and uniform running-in of the bearing, minimal wear and optimal sliding of the part.

Types of babbitt

The general group of babbitts includes several types of alloys, which differ from each other in the chemical element taken as the basis:

• Lead. Consists of lead and antimony, taken in a ratio of 87% to 13%. This connection is inferior to its analogues in elasticity, therefore it is used for the manufacture of unloaded bearings.
• Tin. The most popular, but also the most expensive type of alloy. It is characterized by increased ductility and wear resistance, due to which it is used in the production of bearings intended for constant intense loads. It is based on tin, antimony, copper, cadmium and nickel.
• Calcium. It is based on lead. Supplements include sodium and calcium. The alloy is characterized by the lowest cost, low thermal conductivity and high density. However, it oxidizes quickly and has low wear resistance. Most often it is used in frame bearing shells for carriages, which are subject to frequent replacement.

Due to the variety of types and properties, babbitt remains one of the most popular antifriction alloys.

Babbitt production

The alloy can be produced in two ways: primary and secondary. The primary method involves the use of original pure ore, the secondary method involves the use of scrap metal. In both cases, to make parts, ore and scrap are smelted into pigs whose weight does not exceed 22 kg. The melting point of babbitt is 240–440°C - the exact number depends on the type of compound. Only clean ingots are taken for melting, since any contamination can negatively affect the quality of the product.

Bearing filling technology

For all types of alloy, a single bearing filling algorithm applies:

1. Degreasing the part
2. Cleaning the bearing shell.
3. Babbitt melting
4. Filling a bearing with babbitt
5. Cleaning and adjustment of the finished product

Alloys are produced in accordance with GOST. Each type has its own standards. For example, calcium babbit meets GOST 1209-90, lead and tin - 1320-74.

Benefits of Babbitt

The popularity and demand of the metal is due to a number of advantages:

• Uniform load distribution and fit. This ensures the fastest possible running-in of the bearing and prevents overheating.
• High strength and minimal friction coefficient. The material is highly wear resistant.
• Low linear expansion rate. In this parameter, the alloy competes with most modern materials.

Price

Babbitt is sold in the form of bars, most often in large volumes and at a negotiated price. The average market price directly depends on the type, brand and manufacturer of the alloy. So a kilogram of brand B16 lead at FerroLabs costs 135 rubles. Tin B83 is more expensive - from 990 rubles. for 1 kg. The average market price of babbitt scrap is about 500 rubles. for 1 kg.

Take a responsible approach to choosing babbitt - the quality of the future product will depend on the type of metal. Give preference to trusted and well-known suppliers who have been on the market for a long time.

Source: https://ferrolabs.ru/blog/splav-dlya-zalivki-podshipnikov-babbit/

Babbitt - what is it?

Babbitt is a special alloy made from lead, tin and other metals. Its main advantage is the low coefficient of friction. This alloy was named in honor of the American entrepreneur and jeweler I. Babbitt, its inventor.

History of creation

This alloy was obtained by I. Babbitt in 1839. The main purpose of its creation was to increase the service life of steam engine bearings. Manufacturers of such units immediately appreciated the excellent performance properties of the new alloy and began to use it widely. In 1841, I. Babbitt, who had previously worked as a jeweler, received a prize of 20 thousand dollars from the US Congress for his invention. This was a turning point in his career. From then on, Babbitt began to study alloys.

In 1844, the metal he discovered was patented in England. And already in 1847, babbitt was registered as a new alloy in Russia.

What is

Copper or antimony is most often used as an additional metal to lead and tin in the manufacture of babbitt. This alloy has high anti-friction properties primarily because it consists of both hard and soft elements. The advantages of babbitt, in addition to the low coefficient of friction, also include wear resistance. Even under heavy load, such an alloy can last for a very long time.

Main area of ​​use

As in the century before last, in our time babbitt is most often used to improve the performance characteristics of bearings and increase their service life. The melt of this metal is poured into their internal surfaces that are subject to friction.

Bearings made using Babbitt, due to the latter’s high anti-friction properties, among other things, also fit more tightly to the shafts. After all, to overcome friction in this case, you need to apply less force.

Babbitt can be used to improve the characteristics of different types of bearings.

The service life of sliding bearings with babbitt directly depends on the thickness of its layer. The lower this indicator, the longer the part can be used.

Advantages and disadvantages

The advantages of this alloy, in addition to the low coefficient of friction and wear resistance, also include low fusibility. The melting point of babbitt is only 240 °C. Also the advantages of this metal are:

• the ability to withstand not only rotational, but also reciprocating movements;
• corrosion resistance;
• high degree of thermal conductivity;
• increased softening at temperatures above 100 C;
• high degree of impact strength.

It has Babbitt filling of the internal parts of the bearings and another advantage. In this metal, among other things, microchannels are formed through which lubricant is supplied to the rubbing elements.

This alloy has practically no disadvantages. However, it still has one rather serious drawback. Unfortunately, babbitt is a metal that is not particularly durable. That is why bearings are not entirely made from it. The body of these elements is made of stronger metals - most often steel.

Main types

Babbitt is, therefore, a metal characterized by very good performance characteristics. In addition, such alloys are also quite simple to manufacture. At the moment, there are only three main varieties of babbitt. This alloy is classified primarily by the type of metal used in its manufacture. Babbitts are distinguished based on this characteristic:

• calcium;
• tin;
• lead.

Calcium Babbitts

The basis of the alloy of this brand is lead. Babbitts of this group got their name because they contain calcium and sodium. The main advantage of alloys of this group is their low cost. Babbitt, made using calcium and sodium, has an increased degree of thermal conductivity and is a very dense material. The disadvantage of alloys of this group is the ability to oxidize very quickly.

Most often, such babbits are used in the manufacture of bearings for railway car frames. This is explained by the fact that railway structures of this type are carefully controlled. Therefore, bearings that fail due to babbitt oxidation are promptly replaced.

Tin alloys

The main advantage of babbitts of this group is their high degree of strength. These alloys, as can be judged by their name, are made from tin. The advantages of this metal, in addition to wear resistance and ductility, also include excellent corrosion resistance.

Tin babbits are also approximately twice as strong as the alloys of the other two groups. Therefore, they are used to manufacture bearings for the most important components of various types of mechanisms and assemblies. Most often, such elements are used in the design of low-speed engines.

In addition to tin, babbitts of this group also include metals such as nickel (can be replaced by cadmium) or copper or antimony. The only drawback of tin alloys is their high cost. The price of bearings made using them is higher than any other.

Lead Babbitts

The main advantage of alloys of this type is resistance to elevated temperatures. Such babbits are made from lead and antimony. They are not particularly elastic.

Therefore, they are not used for the manufacture of bearings that are subject to heavy loads during operation. Also, babbits of this group, unfortunately, are not resistant to rust.

Bearings made using them are used in the assembly of mainly only agricultural heavy equipment and automobiles.

Application in bearings

The scope of use of babbitt is thus quite wide. This alloy can be used for the manufacture of bearings:

• connecting rod;
• indigenous;
• intended for compressors, ship water pipelines;
• used in heavy engineering.

Babbitt brands

When choosing such an alloy for the manufacture of bearings, manufacturers, among other things, should pay attention to its grade. There are only six of these - B88, 83, 83S (for tin alloys), B16, N, S6 (for lead alloys). Babbitts are metals that are marked depending on the proportions of their constituent components - copper, cadmium, nickel.

In any case, when manufacturing alloys of this type, GOST requirements must be observed. Lead and tin babbits are made according to GOST 1320-74, calcium ones - according to GOST 1209-90.

Zinc and aluminum alloys

There are, as already mentioned, three main varieties of babbitts. However, in the production of bearings, alloys of this group can also be used, such as:

Babbitts of these two varieties are rarely used in industry. But sometimes bearings are made using them. The main advantage of aluminum babbits is their low cost. In zinc alloys, the soft element is the eutectic, and the hard element is Al or CuZn3. The main component of such babbitts is zinc.

GOST requirements

According to the standards, a babbitt of any group must:

• be made of primary or secondary metals, cast in pigs weighing no more than 22 kg;
• smelted into pigs with a clean surface, without various kinds of slag contamination.

According to GOST, the babbitt ingot must be absolutely homogeneous when broken. This alloy must be produced in workshops equipped with ventilation systems. According to the standards, the proportion of lead in the air of the working area at an enterprise should not exceed 0.01/0.005 mg/m3, antimony - 0.5/0.2 mg/m3.

Who produces

This alloy is supplied to the market, of course, mainly by metallurgical enterprises. For example, companies such as:

• LLC "Plant Uralprokat"
• LLC "Aurema"
• Perm Experimental Metallurgical Plant LLC.
• Tsvet-Met Market LLC.

There are other large babbitt manufacturers on the market. This metal costs, depending on the variety and brand, in the range of 200-800 rubles per kilogram.

Source: https://autogear.ru/article/336/675/babbit---eto-chto-takoe/

Babbitt scrap - what is babbitt, price

Babbitt is an alloy based on tin or lead, which has high anti-friction properties. The compound received its name from its inventor, Isaac Babbitt. The scope of its application is directly related to the properties of the material: coatings applied from this metal significantly increase the wear resistance of rubbing elements. Wikipedia calls Babbitt the first bearing alloy.

Main connection brands

Babbitt is manufactured in accordance with the technical specifications presented by GOST 1320-74. Finished products are supplied in ingots, which are used for casting bearing assemblies and other parts. Based on the chemical composition of the compound, the following brands of babbitt are distinguished:

• B88 is the most valuable alloy grade at non-ferrous scrap metal acceptance points. Contains about 88% tin. Antimony and copper have the highest concentration of alloying elements: 7.8 and 3.5%, respectively. Cadmium and nickel are also present;

• B83, B83S are also a significant option for secondary metal. The concentration of tin is 83%; of the remaining additives, the highest content remains for antimony 12% and copper 6.5%. The second version of the alloy contains pigs, which is absent in the first name, as well as in the B88 brand;

Sliding bearings and babbit B-83

• B16 - characterized by a high concentration of lead 65 - 70%. The proportion of tin and antimony is the same, ranging from 15 to 17%, while the copper content is 2%;

Babbitt B-16

• BN - the lead component exceeds 70%, while tin is included at the level of 10%. Additives include antimony, copper, cadmium, nickel and arsenic;

• BS6 is the most lead-containing grade of alloy (about 90%).

The document does not cover all modern variations of the connection, however, the presented brands remain the most popular in domestic production.

As you can see, all types of alloy can be conditionally classified into two types: tin and lead babbits. Naturally, the area of ​​application, as well as the sources of babbitt scrap, will depend on the prevailing element.

Tin grades of compounds are distinguished by improved resistance to wear, corrosion, and better thermal conductivity. Their scope of application includes specifications where a minimum coefficient of friction is required, hence an increased level of viscosity.

Lead-based alloys are characterized by increased operating temperatures, and therefore are used to improve the antifriction characteristics of bearings in diesel engines and rolling mills. Babbitt is also present in railway transport. Rolling stock bearings contain a lead-calcium variation of the alloy.

Sectional view of a sliding bearing filled with Babbitt

Viewpoint of the generally accepted standard for babbitt scrap

Waste compounds established by GOST 1639-2009 fall under the categories of secondary tin and its alloys:

1. Lump babbitt scrap. The category contains exclusively tin alloy grades. Main components of recycled metal: diesel and turbine bearings.
2. Lump waste with high lead content. Standard scrap bearings are complemented by used typographic elements.
3. Shavings of tin-lead alloys. This group includes only tin babbit processing waste.
4. Mixed shavings. It presents brands of lead compound variations.

Naturally, the main material value among babbitt scrap is represented by its varieties with a high tin content. The cost per kilogram of such scrap is close to the price of pure metal.

Due to the variety of alloy grades, as well as the impossibility of visually distinguishing different types of babbitt, spectral analysis is often used. Reception points for non-ferrous scrap metal, equipped with special analytical equipment, make it possible to accurately determine the concentration of tin, which can have a positive effect on the final price of accepted babbitt scrap.

Babbitt scrap price

Average prices for Babbitt scrap in Russia are presented in the table below. Remember that these prices are not an indicator, because... Some company may give a higher price, and some lower. The prices in the table are just a guide to give you an idea.

These are the most popular brands of Babbitt that accept

Scrap tin-lead alloys for 1% in kg	9.2 rub/kg
Babbitt B-83 crowbar	940 rub/kg
Babbitt B-16 crowbar	162 RUR/kg
crowbar babbitt marriage	5 rub/kg

Interesting features of using an anti-friction compound

As can be seen from the GOST categories, the main area of ​​use of babbitts is bearing products, i.e. You need to look for babbitt in scrap bearings. However, the connection is characterized by a low fatigue resistance value. This narrows the range of applications of the alloy to bearings with a durable steel or bronze housing. The thickness of the poured babbitt layer affects the service life of the products: thinner (up to certain limits) layers of the alloy extend the working life of the part.

Source: http://xlom.ru/vidy-metalloloma/lom-babbita-chto-takoe-babbit-cena/

What is babbitt, price for 1 kg of scrap at collection points

When evaluating babbits, producers of non-ferrous scrap are guided by the chemical composition and condition of the metal.

Today, babbitt is accepted at collection points at prices ranging from 50 to 1,200 rubles per kg.

A person who does not know the basic characteristics may become a victim of deception by an unscrupulous scrap buyer.

What is Babbitt and where is it used?

Babbitt is a soft alloy containing particles of hard metals. Used as a solid lubricant in bearings and friction parts .

When the alloy is poured or sprayed onto the inside of the bearing shell, a ring is formed, which, with a constant supply of oil, increases the wear resistance of the parts.

The antifriction alloy is based on tin and lead, which have high thermal conductivity and a low coefficient of friction.

Depending on the purpose, the following is added to the alloy :

• copper:
• antimony;
• calcium;
• aluminum, etc.

Based on the composition of the main raw materials, babbits are divided into three categories :

• lead;
• tin;
• calcium

Lead alloys

Lead babbits are the most common due to their low cost; they are used for filling parts that are not subject to heavy loads.

The composition of the additives is marked :

The main composition of the B16 alloy is lead. The number 16 indicates the percentage of tin content, additional impurities - copper and antimony.

A special feature of this babbitt is its ability to withstand high temperatures for a long time.

The main disadvantage is that under heavy loads and vibration the alloy cracks and crumbles.

Mainly used for filling bearings of railway and water transport, during which they are often changed during operation.

Babbitt B16 can also be found in:

• bearings of low-power diesel engines;
• ball and tube type mills
• turbines rotating under steam or water pressure;
• compressors;
• crushing plants.

BN is babbitt, which can be used instead of B16; it also contains up to 11% tin and 5 additional substances:

• antimony (up to 15%);
• copper;
• cadmium;
• arsenic;
• nickel.

Thanks to these additives, bearings with a BN babbitt liner are stronger. Most often used in diesel generators and compressors.

Lead alloy BS6 withstands shock loads and is in demand in parts of tractor engines.

Marking according to GOST:

Tin alloys are more expensive. In terms of physical and antifriction properties, they are superior to lead ones.

The most popular alloy is B83 , the main composition of which includes up to 85% tin, antimony and copper.

Widely used in bearings rotating at high speeds under medium loads.

High wear resistance extends the service life of the equipment, but, just like Babbitt B16, B83 does not withstand shock loads and vibrations .

They are used in mechanisms whose operating principle is based on turbine rotation.

It can be:

• bearings ;
• turbochargers;
• low speed diesel engines

A more successful modification of this alloy is the B83s , the chemical composition of which allows it to be used as a solid lubricant in components of mechanisms operating with impact force.

B88 is the most expensive Babbitt tin alloy . From the marking it follows that the average percentage of tin content is 88%. Withstands not only high temperatures, but is also resistant to high dynamic loads and vibration shocks. It is actively used in heavy mechanical engineering and in other industries associated with bulky rotating mechanisms.

Lead-calcium alloys are produced under the markings:

These babbits are used mainly in moving mechanisms of railway transport, as well as for filling main and connecting rod bearings of diesel and gas engines.

Source: https://rcycle.net/metally/cvetnye/chto-takoe-babbit-tsena-za-1-kg-loma-v-punktah-priema

Metal: what it is, its physical properties, what it consists of

05Dec

articles

The discovery of common physical and chemical properties of metals and alloys led to widespread use of the material. Over time, scientists began to study its characteristics in detail, as well as create various metalworking methods that increase strength and improve the crystal lattice. At the moment, there are such compositions that are used in shipbuilding.

More and more areas of life cannot do without metal elements - from a household spoon or fountain pen to complex mechanical components and microcircuits. But ordinary people often do not understand what kind of substance we use and what features make it so widespread. In the article we will talk about this in detail.

What is it - metal

The ancient Greek word metallion just means “to dig out of the earth” - mined from rock ore. Currently, 96 pure values ​​and an unlimited number of alloys are known. All of them differ from non-metals in their increased strength properties and conductivity, which is why wires are made from them. At first glance, you can distinguish a metal sample from a stone or other one by its specific shine.

Physical properties

At room temperature and without applying pressure, all substances are solid. But there is gallium, which already at 30 degrees of heat begins to deform and melts in your hands. Characteristics you can note:

• High plasticity. Only manganese, tin and zinc are fragile.
• Can be light or heavy. Compare aluminum with osmium.
• The melting point is very high. There are exceptions, for example, mercury, which is why it is used in classic thermometers.
• Color – gray, silver, bluish. Colored items, such as yellow or red, are rare.
• Increased conductivity of heat and electricity, especially in copper, is why copper wires are popular.

Basic chemical properties of metals

There are no general rules in this category, since they are all divided into many subgroups according to activity level - alkaline, actinides, semimetals and others. Many interact with water, almost all interact with oxygen (except gold and platinum), and oxidation occurs. The process takes place under normal conditions if there is a lot of click in the composition, only when heated - if not. Also, almost all elements react with sulfur and chlorine.

Signs

We list the features by which the average person can distinguish substances of this category from non-metals:

• fishing line
• Good conductivity of heat and electricity.
• Strength.
• Can be forged and welded.
• Crystalline body structure.
• High melting and crystallization temperatures.

Classification and types of metals

There are pure, single-component structures and alloys. The most classic example is the different types of steel. They differ according to GOST in accordance with the addition of alloying additives. The higher the carbon content, the stronger the material. There is also a generally accepted distinction; below we present the subtypes.

Black

They are mined from metal ore. In production they occupy 90% of all raw materials. Usually these are cast iron and steel. To change the characteristics, more or less amount of carbon and alloying additives are added: copper, silicon, chromium, nickel.

One of the very popular subspecies is stainless steel, which is distinguished by its shiny surface and unique properties - lightness, high strength and resistance to humidity and temperature changes.

What applies to non-ferrous metals

The second name is non-iron, that is, alloys do not contain iron, but consist of more expensive materials. Substances have different colors and have unique qualities:

• durability;
• long-term preservation of properties;
• the formation of an oxide film that prevents corrosion.

Thanks to this, certain varieties can be used in medicine, jewelry, the chemical industry, and in the manufacture of electrical wires. Non-ferrous metals include aluminum, zinc, tin, lead, nickel, chromium, silver, gold and others.

Copper and its alloys are popular metals

Copper ore was one of the first to be processed by man because it is subjected to the cold method of forging and stamping. Pliability has led to demand everywhere. Oxygen in the composition leads to a red tint. But decreasing the valency in various compounds will lead to yellow, green, blue color. Excellent thermal conductivity is considered an attractive quality - second only to silver, which is why it is used for wires. Connections can be:

• solid - in combination with iron, arsenic, zinc, phosphorus;
• with poor solubility with bismuth, lead;
• fragile - with sulfur or oxygen.

Metals include aluminum and alloys

Al was discovered in 1825 and is distinguished by its ease and simplicity in metalworking. It is made from bauxite, and the reserves of this rock are practically inexhaustible. Next, the element is combined in various proportions with copper, manganese, magnesium, zinc, and silicon. Less often with titanium, lithium, beryllium. Features depending on additives:

• good weldability;
• corrosion resistance;
• high fatigue strength;
• plastic.

It is used for the manufacture of jewelry, cutlery, as well as for glass melting, in the food and military industries, for the creation of rockets and for the production of hydrogen and heat in aluminum energy.

All about the metals magnesium, titanium and their alloys

Mg is the lightest substance of this group. It does not have strength, but it has advantages, for example, plasticity, chemical activity. Due to its high structural ability, it is added to compositions to increase weldability and ease of metalworking with a cutting knife. It must be taken into account that magnesium is very susceptible to rust.

Titanium has similar qualities - lightness, ductility, silver color. But the anti-corrosion film appears upon first contact with oxygen. Distinctive features are low thermal conductivity, electrical conductivity, and lack of magnetism. Metal containing titanium is a substance used in the aviation, chemical, and shipbuilding industries.

Anti-friction alloys

A characteristic feature of this group is its ease of use under mechanical stress. They create virtually no friction and also reduce it in other composites. Very often they act as a solid lubricant for components, for example, for bearings. The composition usually includes fluoroplastic, brass, bronze, iron graphite and babbit.

Soft

These are those whose metal bonds are weakened. For this reason, they have a lower melting and boiling point and simply become deformed. Sometimes you can make a dent with one finger press, or leave a scratch with your fingernail. These include: copper, silver, gold, bronze, lead, aluminum, cesium, sodium, potassium, rubidium and others. One of the softest is mercury; it is found in nature in a liquid state.

What does hard metal mean?

In nature, such ore is extremely rare. The rock is found in fallen meteorites. One of the most popular is chrome. It is refractory and can be easily processed into metal. Another element is tungsten. It melts very poorly, but when properly processed is used in lighting applications due to its heat resistance and flexibility.

Metal materials in the energy sector

We would not have such a developed electrical network and a lot of devices that consume electricity if a number of substances were not distinguished by the presence of free electrons, positive ions and high conductivity. Wires are made from lead, copper and aluminum. Silver would be great, but its rarity affects the cost, so it is rarely used.

Features of Ferrous Secondary Metals

This is waste that is generated as a result of one of the metalworking stages - forging, cutting. These could be scraps or shavings. They are sent to steel-smelting furnaces, but before that they must pass inspections in accordance with GOST. Scrap is called ferrous metal, it is distinguished into steel and cast iron according to price. Its use is in great demand instead of ore processing.

Alkaline earth alloys

These are solid substances that have high chemical activity. They are very rarely found in their pure form, but are used in compounds. Their importance cannot be overestimated from the point of view of human and animal anatomy. Magnesium and calcium are essential microelements.

Alkali metal concept

They are able to dissolve in water, forming an alkali. Due to its increased chemical activity (reaction occurs with violent action, ignition, release of gas, smoke) it is almost never found in nature. After all, at the external level there is only one electron, which is easily given to any substance. Hydroxides are very important in industry.

General characteristics of materials from the d- and f-families

These are transition elements that can be both oxidizing and reducing agents. Properties depend on the environment in which they are located. But there are also common ones:

• there are many electrons in the outer level;
• several oxidation states;
• increased valence;
• strength;
• ductility;
• ductility.

What are the side subgroups of metals in the periodic system?

In fact, these are varieties of the previous category - transitional elements. This is a line from scandium to zinc. They are often smelted and have virtually the same characteristics as the above materials from the d- and f-families.

Alloys

Pure ingots mined from ore are used as rarely as possible. This is due to both high cost and insufficiently good qualities (to correct it, carbon and alloying additives are added). Sometimes compounds occur in nature, and you just need to adjust the composition. The most famous:

• brass;
• bronze;
• steel;
• cast iron.

Comparison of properties

The second part of the elements in the periodic table is characterized by a variety of characteristics, so it is almost impossible to provide a complete summary table. We offer a table that shows 4 distinctive features:

Signs	Metals	Nonmetals
Position in P.S.	Under the diagonal boron-astatine	Above her
Atomic structure	Large atomic radius, pure electrons in the last layer - from 1 to 3	Small, from 4 to 7 - respectively
Physical properties	Electrical conductivity, thermal conductivity, gloss, malleability, plasticity, in terms of state of aggregation, mostly solid	Dielectrics, non-shiny, brittle, gases, liquids and volatile solids
Crystal lattices	Metal	Molecular, atomic
Chemical properties	Restorers	Oxidative (sometimes reduced)

We talked about metal, what kind of material it is, how it is used. If you need metalworking machines, order them from the Rosta company.

Source: http://rocta.ru/info/metall-chto-ehto-takoe-ego-fizicheskie-svojstva-iz-chego-sostoit/

Babbitt is a pig

Babbitt in pigs is a common form of production of babbitts, which are subsequently used for spraying on sliding bearing shells, or for pouring them, used in a variety of equipment and machines.

Babbitt pigs, due to their configuration and various parameters, can be of various shapes, which makes it easy to select the optimal specimen for a particular product. Each babbitt pig can be different in its chemical composition.

The quality of products is regulated by GOST 1320-74.
The same standard defines mechanical and physical characteristics, high precision performance, as well as surface treatment. The product is delivered in packages on pallets, tied with tape.

Properties and characteristics

The structure of babbitt is an alloy containing lead. The main difference between babbitt pigs and products whose structure contains tin is the ability to use them at elevated temperatures.

In addition to lead, babbitt pigs contain elements of copper, antimony and tin. Metal, when heated to 100 degrees, turns out to be quite plastic. The melting point ranges from 320°C to 440°C.

The most optimal operating temperature for babbitt pigs is up to 110 degrees.

To improve quality, alloying additives are added:

• arsenic – increases hardness and strength;
• nickel – has a positive effect on wear resistance, hardness, and increases tensile strength;
• tellurium – helps increase ductility;
• cadmium – increases corrosion resistance;
• magnesium is a modifier;
• sodium – strengthens an alloy containing soft lead due to the formation of a solid sodium solution in lead;
• calcium - introduced as a substitute for tin.

Babbitt pigs of alloy B16 have weaker anti-friction properties, while at the same time, alloy B83 is a high-quality product. Products with weak antifriction properties, type B16, are not recommended for use under mechanical vibrations, as this leads to crumbling of the alloy and the appearance of cracks in the product.

buy babbitt in the form of pigs, weighing no more than 22 kg.

The main disadvantage of all babbitts is their low fatigue resistance, which impairs the performance of the sliding bearing. Because of this drawback, babbitt pigs can only work successfully on liners that have a durable steel (cast iron) or bronze body.

Thin-walled liners are typically used in automotive internal combustion engines, manufactured by stamping from a bimetallic alloy obtained by continuous casting. The lifespan of the bearings is affected by the thickness of the babbitt layer poured onto the metal base.

The smaller the babbitt layer, the longer the service life of the liner.

History of Babbitt

Babbitt pig got its name in honor of Isaac Babbitt, who was an American inventor. While making jewelry, he began to experiment with the composition of various alloys, providing less labor-intensive processing. In 1824, he managed to open the first factory in the United States in his city, which began to produce a cheap combined metal that acted as a substitute for silver. It consisted of copper, antimony and tin.

15 years later, in 1839, he managed to invent the now famous anti-friction alloy of Babbitt. This invention was awarded a gold medal by the Massachusetts Mechanics' Association in 1841. The US Congress bought the patent for the invented alloy from Babbitt for 20 thousand dollars. Despite this, Babbitt continued to experiment with various alloys. In addition, he was also involved in making soap.

Since 1847, production of babbitt on an industrial scale began in Russia.

Babbitt B83

Babbitt ingot B83 is one of the most low-melting alloys with excellent anti-friction characteristics, used in the production of liners. The alloy structure consists of 84.5% tin, 6.5% copper and 12% antimony. In addition, the following were added to the alloy structure:

• iron;
• lead;
• aluminum;
• bismuth;
• arsenic;
• zinc and other elements.

This product has excellent wear resistance, at a relatively low cost, maintaining its original properties when the temperature rises to 110 degrees. It is not recommended to operate these products under vibrations and shocks due to excessive fragility.

Permissible operating pressure is from 10 to 15 MPa.

Babbitt B83 pigs are not susceptible to the effects of water, thanks to the tin in the composition - they are not destroyed when exposed to weak alkalis and acids. The most favorable temperature for operation is about 80°C.

B83 is widely used for the manufacture of sliding bearings operating at medium loads under high-speed conditions. Their most common use is in marine engines, turbines and turbochargers.

Babbitt B16

Babbitt pig B16 (lead babbit) has weaker anti-friction properties compared to B83, and operation of products under conditions of mechanical vibration can crumble the alloy with the appearance of cracks in the metal. Therefore, these products are used for quiet operating conditions.

B-16 is cheaper than tin alloy. The main advantage of Babbitt B-16 is the presence of hard inclusions in the alloy, thanks to which the antifriction characteristics of the product are optimized, which ensures longer operation.

Allowable operating pressure is 10 MPa.

Tin

Among tin alloys, there are about 35 alloys that are used in various industries. The most popular and in demand tin babbit is B83. Harmful impurities that enter the composition of alloys and due to imperfections in the production process are less than 1% in the composition of this multicomponent metal.

Compared to lead babbitts, tin ones are characterized by increased resistance to corrosion, thermal conductivity and wear resistance. They are used in cases where such characteristics as minimum friction coefficient and increased viscosity are important.

Lead

Compared to tin, they are characterized by a higher operating temperature. The increased lead content in the composition makes the B16 alloy harder and denser. Density is 9290 kg/m3. The most popular pigs are Babbitt B16.

The antifriction properties of lead babbits are somewhat inferior to tin ones, but their cost is also lower. The number on the stamp indicates the tin content. Lead babbits work most effectively in quiet conditions, without shock loads; the work intensity should not exceed 30.4 MPa•m/s.

They are used in lightly loaded units (rolling mills, diesel engines, motor-axial bearings, saw frames, etc.).

Lead also includes BN, BK2Sh, BKA, BSb, BK2 and others.

Lead-calcium

Babbitt pigs of this type contain, in addition to lead, sodium and calcium additives, which have a direct impact on the technical characteristics of the alloy and its scope of application. Lead calcite contained in the composition provides anti-friction properties. Sodium affects the mechanical properties of the metal - it increases its hardness. If aluminum is also present in the composition, this has a positive effect on both anti-friction properties and strength.

Lead-calcium BKA is most often used for the production of bearings. Thanks to heat treatment at a temperature of 60°C (acceleration of the natural aging process of the metal), mechanical properties increase. The recommended operating temperature is no more than 60 degrees Celsius, because As the temperature increases, the hardness decreases significantly.

Ingots of BKA and other lead-calcium compounds are cheaper than tin and lead ones. But they are also inferior to them in corrosion resistance (they oxidize quite quickly in air) and strength. Bearings made from BKA babbitt pigs are used mainly in railway production, because do not experience critical loads and are changed quite often as planned.

Production of babbitt pigs

The production of babbitt pigs can be based on the use of either ore or scrap metal. More than 70% of the total share of babbitt production is made using recycled materials.

Melting pigs is a fairly cheap process, which is due to the low melting point of babbitt. This type of technological operation is carried out in special electric furnaces, and often only 25-27 kW of power is sufficient. The biggest difficulty is to smelt semi-finished products with strict adherence to the chemical composition of the alloy, because deviation from the indicators stated in the standards will affect the technical characteristics of the metal.

They produce babbitt pigs weighing up to 22 kg, in accordance with state standards. Products with other weights, in some cases, can be produced to order.

When smelting any products from Babbitt pigs, they must first be thoroughly cleaned of any contaminants and degreased. Only then are they sent to the ovens.

Babbitt price

The cost of pigs is determined based on the quality of the product, the method and complexity of its manufacture, processing method, weight and overall parameters. The pricing policy is influenced by the size of the lot for sale. The higher the sales volume, the cheaper the cost of the products.

Also, prices are affected by leverage and delivery conditions, storage time of the paid goods in the warehouse, packaging methods, as well as seasonal price fluctuations.

Application

Pig pigs are widely used in ship and railway equipment. Bearings are used on electric and diesel locomotives and steamships. These bearings are widely used on low-speed diesel engines. In addition, alloys of this type are used:

• in the manufacture of mills of various types (ball and pipe);
• in the production of rolling mills;
• in the manufacture of plain bearings in turbines;
• in the manufacture of generators and compressors.

Supplier: LLC RTG "MetPromStar"

Source: https://www.okorrozii.com/metalloizdeliya/babbit-chushka.html

Properties of babbitt

Let us list the main remarkable properties of the alloy:

• antifriction material - resisting friction (reciprocating movements of the “back and forth” type);
• corrosion resistance;
• low hardness (HB 13-32);
• wear resistance;
• high thermal conductivity;
• not too high melting point - 240-340 degrees Celsius;
• increased softening of the alloy at 100 degrees Celsius (HB 9-24);
• increased impact strength.

Types and grades of alloy

There are three types of babbitt brands, depending on the base metal:

1. Calcium. Although its base is lead, the alloy gets its name from one of its components - it also contains calcium and sodium. These elements distinguish this babbitt at the most inexpensive price and give it increased thermal conductivity and density. But at the same time, such an alloy oxidizes faster, which does not add wear resistance to it. Therefore, calcium babbitt is in most cases used in frame liners of cars, both freight and passenger - there they are most often checked and, if necessary, quickly replaced.
2. Tin. The basis of this babbitt is tin, which is characterized by a high coefficient of friction, high wear resistance and ductility, and increased corrosion resistance. This alloy is approximately twice as strong as its “brothers”. Therefore, this brand of Babbitt is indispensable for bearings that bear the maximum load and play an important role. Their area of ​​application is various low-speed engines. In addition to tin, this alloy contains either cadmium and nickel, or antimony and copper. The only disadvantage of tin babbitt is its highest price among these alloys.
3. Lead. The soft components here are lead and antimony - 87% and 13%, respectively, in this segment. The solid element of the alloy is crystalline antimony (5% of the total volume). This babbitt is not particularly elastic, which is why it is used for the production of bearings that are not particularly loaded. However, it is remarkable in that it perfectly tolerates high-temperature heating of the element. It is worth noting that such babbits are more susceptible to corrosion than others. Their path is diesel engines of tractors and cars.

Lead babbitt grades - B16 (lead is the main element), BS6, BN (lead, tin, nickel, copper, arsenic, cadmium, antimony). They, like tin ones, are produced in accordance with GOST 1320-74. Calcium alloys comply with GOST 1209-90; their varieties are BK2, BKA, BK2TS, BK2SH.

Brands of tin babbitt are B83, B83S (small addition of lead), B88. Variety B83, for example, is 80% tin component, 12% antimony, 6% copper and, on average, 0.1% each of bismuth, lead, iron, arsenic, and aluminum.

And B6 is 88% lead, 0.3% copper, 0.1% iron, a small proportion of zinc and arsenic.

Babbitt melting

To obtain such alloys, both primary metals—primordial ore—and secondary metals—remelting scrap metal—are used. In addition to the main components listed in the previous paragraphs, cadmium, arsenic, sodium, and tellurium are added to babbits.

Babbitts B16, BN, B88 and others are cast into ingots (ingots), characterized by a strictly defined mass. It is also important that the slightest contamination is not observed on the surface of the ingot - even such a factor can negatively affect the quality of the bearing.

The brand of Babbitt also affects the melting point of the alloy. Thus, the most popular babbit B83 melts at a temperature of +240 degrees Celsius, and tin B83 melts at +340-440 degrees on the same scale.

Babbitt cost

Let's consider the cost of this alloy in the Russian Federation. The price directly depends on the properties of babbitt and its brand. Thus, the average price of lead babbit B16 is about 350 thousand rubles/ton. The cost of B83 alloy is about 1.3 million rubles/ton.

If we consider the market for recyclable materials, then 1 kg of babbitt scrap metal can be sold for a maximum price of 500-600 rubles/kg. Basically, such alloys are purchased for their subsequent disposal, because unnecessary bearings can cause irreparable harm to the environment, since cadmium, lead, and antimony are literally poisons for the nature around us.

Babbitt alloys are far from a modern invention. However, they are still relevant in mechanics today, namely in the production of bearings.

This is observed due to the fact that babbits are durable, wear-resistant, quickly and tightly rubbed into the part, ensure noiselessness during friction and, due to their low thermal conductivity, eliminate engine overheating.

In addition, manufacturers offer dozens of different brands of babbitts, each of which corresponds to a specific type of both the bearing and the entire engine of the machine.

Source: https://monateka.com/article/238625/

Babbitts

Babbitt is an artificially created alloy of metals with different chemical properties. These alloys are based on metals that have a low melting point. These metals include lead, tin, arsenic and antimony.

Since some elements are softer and others are harder, the result is a specific alloy that has good properties that reduce the coefficient of friction (the so-called antifriction properties), wear resistance and durability.

Babbitts

The invention of such materials belongs to that category of scientific curiosities when the main activity of the inventor is far from the subject of the invention. The priority for the invention of alloys, which are used in many mechanisms, belongs to Isaac Babbitt, a professional jeweler. He patented his invention back in 1841 and even received a huge prize for those times from the US Congress - $20,000. Six years later he appeared in Russia.

Babbitt classification

Today the following brands have been well studied and developed:

• tin;
• calcium;
• lead.

All of them are produced in accordance with GOST. For example, calcium babbits are manufactured on the basis of GOST 1209-90, tin and lead babbits according to GOST 1320-74.

Download GOST 1209-90

Download GOST 1320-74

Each of the three brands is classified using a set of capital letters and numbers:

• tin babbits are marked B83, B83S, B88, SAE11, SAE12, ASTM2;
• lead babbits are marked B16, BN, BS6, SAE13, SAE14, ASTM7;
• calcium babbits are marked BK2, BK2SH, BKA.

Main characteristics and composition

The properties of the listed brands are assessed based on the following characteristics:

1. Full composition of the chemical elements of the alloy.
2. Physical characteristics of the alloy.
3. Foundry - technological characteristics.
4. Mechanical properties.
5. Maximum permissible operating modes.
6. Scope of application of the alloy.

In terms of chemical composition, they differ in what metal was chosen as the basis. For example, tin babbit B83 includes up to 85% tin (Sn), up to 12% antimony (Sb), about 6% copper (Cu). Lead babbitt B16 contains 87% lead (Pb) and almost 13% antimony. The main metal in calcium babbitts is lead: up to 96% with the addition of calcium (Ca), about 1%.

To give babbitts the required properties, solid elements are included in their composition. These elements include almost the entire group of rare earth metals: cadmium, tellurium, antimony and others.

https://www.youtube.com/watch?v=GYwtB889VVA

Among the physical characteristics, the most interesting are: specific gravity, density, resistance to electric current. For all the obtained alloys these indicators are very close.

Babbitt brand B83

Of the casting and technological characteristics, an important role is played by: the melting point and the temperature at which it is necessary to pour the alloy into the bearing. It depends on additional chemical additives.

For example, the melting point of B83 grade tin babbitt is 370°C, and the pouring temperature should be 440°C. For alloy grade B16 (lead babbitts), the melting point is 410°C, the temperature during pouring should exceed 480°C.

These examples clearly show that when pouring such alloys into a bearing, the melt temperature must always be higher than the melting point.

Today, on an industrial scale, babbits are produced either from the ore of the corresponding metals, or from secondary raw materials supplied for processing. Based on technological feasibility, babbits are produced in the form of ingots. The weight of each ingot is 22 kg.

To combat illegal production and organize an accounting system, each ingot is stamped with the manufacturer’s trademark. It indicates the serial number of the melt produced according to factory registration. These ingots are then used to cast into bearings.

Babbitt bars

Mechanical properties include: permissible dimensions of products, tensile strength of casting under short-term load, relative elongation, impact strength and hardness.

The maximum permissible operating conditions are assessed based on the following characteristics: permissible load, rotation speed of the part, hardness of the rotation shaft, permissible heating temperature of the parts.

The scope of application of a certain type of babbitt is determined by the following characteristics: type of load, specific pressure, circular speed, work intensity and maximum operating temperature.

Depending on its individual properties, each type of babbitt is used strictly in certain mechanisms and machines. All of them are used to fill the side walls of the bearing mounting shaft. This helps to significantly reduce the coefficient of friction that prevents the bearing from rotating normally.

Having a relatively low melting point, it is possible to obtain a good effect when gradually rubbing in rotating parts. It can significantly reduce the wear of new bearing elements and increase their service life. In addition, when the bearing rotates, microchannels are formed in the babbitt.

Through them, lubrication of all rotating parts is improved.

Each brand of Babbitt has a specific area of ​​application. For example, tin babbits are used when increased wear resistance at high rotation speeds is essential. Such grades are especially in demand when it is necessary to ensure good viscosity, acceptable temperature readings and a low coefficient of friction.

Good corrosion resistance allows these types of babbitts to be used in conditions of high humidity and even in water.

For example, the B83 babbitt discussed above is used in bearings operating at very high speeds and increased dynamic loads. These can be high-speed diesel engines, the lower halves of the so-called crosshead bearings of low-speed diesel engines. In addition, they are used in crank and frame bearings, as well as in bearings that support propeller shafts on ships.

Lead babbits withstand high heat best. They are used in diesel engines of cars, tractors, and excavators. B16 brand babbits are used in bearings located in electric locomotive engines. They are installed on various track machines and in equipment used in heavy engineering.

Babbitt brand B16

Calcium babbits are used in railway transport, to equip rolling stock, both diesel locomotives and freight and passenger cars.

Advantages and disadvantages of the listed alloys

All the described alloys have certain advantages and characteristic disadvantages. The advantages include:

• high antifriction properties of babbitts (resist reciprocating movements of mechanisms);
• good anti-corrosion resistance;
• high wear resistance;
• increased impact strength;
• relatively low melting point of babbitt (range is 240°C - 340°C);
• increased softening coefficient of the alloy (at a temperature of 100°C it corresponds to the HB 9-24 standard);
• significantly increased viscosity under shock loads;
• good wear resistance;
• The time required for running in individual parts is reduced.

The disadvantages are as follows:

• low strength compared to other alloys;
• low strength (HB 13-32);
• the need to use more durable shells (cast iron, steel or copper);
• low fatigue resistance, which reduces the performance of the bearing and reduces its service life;
• high thermal conductivity;
• the presence of additional additives from arsenic and bismuth make this alloy difficult to recycle;
• for tin babbitts, the disadvantage is the high final cost of the bearing.

Despite these disadvantages, babbits have become widespread in many areas of mechanical engineering. Their positive properties make it possible to solve complex engineering and technical problems.

Source: https://stankiexpert.ru/spravochnik/materialovedenie/babbity.html

What is babbit - Meaning of the word babbit

bab-bit

Noun, inanimate, masculine, 2nd declension (declension type 1a according to the classification of A. A. Zaliznyak).

Root: -babb- ; suffix: -it [Tikhonov, 1996].

Pronunciation

• MFA: units h. [bɐˈbʲit] pl. h. [bɐˈbʲitɨ]

Meaning

1. tech. an alloy based on tin or lead, characterized by a low coefficient of friction and used for casting plain bearings ◆ No example of use (see recommendations).

Related words

Closest relationship

adjectives: babbitt, babbitt

Etymology

Comes from English. babbitt (babbit) “babbitt”, further from proper. Babbitt “Babbitt” (the surname of the American inventor), further from his own. ; barbarian”, then apparently onomatopoeic.

Bibliography

babbitt

Noun.

Root: —.

Babbitt, its types, properties, composition and application

In 1841, the world learned about an anti-friction alloy with the strange name Babbitt. It was created by jeweler Isaac Babbitt, who in his free time was fond of searching for new types of materials. This discovery was a turning point not only for the inventor, but also for the production of bearings. Bearings made from babbitt were distinguished by increased peripheral speeds, which made it possible to significantly increase the load transmitted by the shaft.

So what is this alloy? Why has the relevance of its application not changed so many years after its discovery?

Composition and properties

Babbitt is a bearing alloy whose main components are lead or tin. Belongs to the group of antifriction materials. Mechanical properties and chemical composition are regulated by the state standard GOST 1320-74.

In addition to the main elements, babbitt includes such metals as:

• Cadmium. Has a positive effect on the corrosion-resistant properties of the alloy.
• Copper. Increases the viscosity of the antifriction alloy, which, accordingly, increases run-in.
• Nickel. Improves mechanical properties, in particular tensile strength, hardness and wear resistance.
• Antimony. Helps reduce adhesion to steel.
• Tellurium. Positively affects the ductility of the alloy.
• Calcium, sodium and aluminum are a group of elements introduced into babbitt as substitutes for scarce tin.
• Arsenic. Increases the strength and hardness of the alloy.

Types of babbitts and their properties

Among the features of babbitts are a low melting point (up to 450 ºС), lack of adhesion to steel surfaces and high workability.

Depending on the chemical composition, babbits are divided into 3 groups: lead, tin and lead-calcium.

Leaded

The most popular lead brand is B16. Its chemical composition consists of 15% tin, 15% antimony, 2% copper. The remaining part is occupied by lead.

Lead babbits have lower anti-friction characteristics, are more fragile and wear-resistant. An increase in the content of antimony and tin in B16 increases the strength properties, but negatively affects its ductility. Copper in this grade eliminates chemical heterogeneity, increases viscosity and slightly increases hardness.

The increased lead content in Babbitt B16 makes it more dense. Density is 9290 kg/m3. Hardness is about 30 units on the Brinell scale. The tensile strength is 8 kg/cm2. Deformation processes begin already at a load of 6 kg/cm2.

Babbitt B16 melts at a temperature of 410 ºС. Complete melting of all solid components of the alloy occurs at 480 ºС.

B16 is fragile. For this reason, its use is limited to impact loads. Bearings based on it are used during quiet operation and at peripheral speeds of up to 120 m/s. The ambient temperature should not exceed 70 ºС. The friction coefficient of B16 is 0.006 units.

Bearings made from B16 are used in the manufacture of turbines for steam plants, rolling mills, compressors, electric motors, hydraulic turbines and sawmill frames.

Lead-calcium 

Babbitt BKA has received the greatest use for the manufacture of bearings. In addition to lead, it contains elements such as calcium (up to 1.2%), sodium (up to 0.9%) and aluminum (up to 0.2%). Antifriction properties are ensured by the presence of the lead calcite compound in the alloy structure. Their role is similar to tin in B83. Sodium increases the mechanical characteristics of BKA, in particular hardness. aluminum babbitt has a positive effect on both strength and friction coefficient.

The mechanical properties of BKA are increased by heat treatment: natural aging. This process is accelerated by additional heating to 60 ºС.

Babbitt does not adhere to the steel and is held on its surface by mechanical fastening. The operating temperature of bearings based on lead-calcium babbits is 60 ºС. As the operating temperature increases, the hardness of the babbitt greatly decreases, which can lead to destruction of the bearing rings.

These bearings have a low price due to the replacement of expensive tin with cheaper metals. But their disadvantage lies in their strength and low corrosion-resistant properties, which lead to oxidation of babbitt in air, and, as a result, a sharp decrease in wear resistance. For this reason, the main application of BKA Babbitt bearings is in railway production, which does not have significant requirements for both load and peripheral speeds.

Production

Both ore and scrap metal are used to smelt babbitts. The share of secondary production in our country accounts for about 75%. Alloys are transported in the form of pigs, the weight of which is strictly regulated by state standards and does not exceed 22 kg.

Melting of pigs is carried out in special chamber-type electric furnaces. This process is relatively cheap. This is primarily due to the low melting point of the alloys. Typically, in medium-scale production conditions, 26 kW of furnace power is sufficient.

When melting, the main difficulty is obtaining the chemical composition stated in the state standard. Any deviation from the norm can lead to a significant change in performance characteristics, which will affect the longevity of the bearing in the future.

For this reason, pigs are pre-cleaned from contamination with special detergents. Next comes degreasing the surface. And only after all these steps have been completed is the babbitt placed in the oven.

Pricing

The price of a babbitt consists of the cost of the metal components included in its composition. First of all, we are talking about tin here. The shortage of this metal in production is growing, and, accordingly, its prices are also growing.

World exchanges serve as the basis for the formation of prices for metals for industrialists. Recently, most manufacturers are guided by the value of quotes from the London Exchange of Ferrous and Non-Ferrous Metals.

The cost is also affected by the volume of scrap supply. In cases of large consignments (over 100 kg), scrap metal collection points make a markup of 5 to 10%.

If we take the average cost of babbitt in Russia, it fluctuates between 500-600 rubles per kilogram.

Source: https://prompriem.ru/stati/babbit.html