Wood alloy what is it - Metals and their processing

What types of solders are there for soldering: types, brands, purpose

To create a tight, reliable connection between metal parts, soldering is most often used. The essence of the process is to bond materials when heated using an alloy - solder, the melting point of which is lower than the melting point of the substances being joined.

When heated, solder, spreading between the joined areas, ensures strong adhesion (sticking) of metals to each other at the molecular level, which gives high strength and electrical conductivity of the connection. The molten solder should wet the metal well. That is, the connection between the molecules of a solid and a liquid must be more reliable than between particles of a liquid material.

In this article we will tell readers of the Sam Electric website what types of solders there are for soldering, having examined the purpose and scope of each brand.

Solder selection

In order for the connection to be of high quality, it is necessary to choose the right solder. To do this you need to consider:

types of metals or alloys to be joined;
soldering method;
temperature restrictions;
size of parts to be connected;
required mechanical strength;
corrosion resistance.

Varieties

Types of alloys intended for the soldering process, depending on the melting point, are divided into hard refractory and soft low-melting compositions. The former melt at 450 degrees and above, the latter below this value. Soldering with hard alloys is more durable. But soft types of solders are indispensable for radio installation work.

Soft or fusible

The most widespread are tin-lead solders, abbreviated as POS. The number indicated in the marking after the letter abbreviation corresponds to the percentage of tin in the composition. For example, POS-60 contains 60% tin. These types are used in the production of instruments and electronic devices.

POS-90 contains only 10% toxic lead, so this variety is used for repairing food utensils and medical instruments.

POS-40 is used for soldering brass and copper pipes, electrical equipment, and elements made of galvanized iron.

POS-30 is used for soldering zinc sheets, in the cable industry, and for soldering galvanized iron.

POS-61 is used for soldering radio components to printed circuit boards. Its melting point is 183 degrees, and complete transition to the liquid state occurs at 190 degrees, which helps to avoid overheating and prevents failure of radioelements.

There is a universal and convenient variety POS-61, which is a hollow tin-lead tube with rosin inside. This form is very convenient, since soldering is carried out without additional flux.

The next type of POS is POSSu brand solder. In addition to the lead and tin components, it contains up to 2% antimony. This material can be used to solder the windings of electrical machines, electrical equipment elements, cable products, and galvanized parts.

The table briefly presents some types of PIC and their main properties.

Currently, lead-free alloys are widely used in the manufacture of electronics. For example, lead-free solder POSu95-5. Its composition can be determined by labeling. The number 95 means the percentage of tin, 5 - antimony. The melting point is in the range of 234 - 240 degrees.

Hard or refractory

Hard types of solders for soldering create high joint strength. The disadvantage of their use is the need for intense heating above 500 degrees, which can damage some types of devices.

Among the refractory ones with a high melting point, two groups are divided: alloys of copper and silver. Copper solders, based on zinc and copper, are used in connections intended for static loads due to their brittleness. They cannot be used to solder materials subject to dynamic shock or vibration loads.

Silver types of solders are universal; they can be used to solder various materials. The disadvantage is the high cost, so the use of the composition must be economically justified. Silver alloy is used for soldering stainless steel, copper, in orthopedic dentistry, and for repairing silver jewelry.

Compositions containing silver are designated by the letters PSr. There are markings PSr-15, PSr-25, PSr-45, PSr-65, PSr-70, where the number indicates the percentage of silver.

Low temperature

The composition of POSK 50-18 includes 50% tin, 18% cadmium, 32% lead. Cadmium enhances corrosion resistance, but makes the material toxic. The purpose of solder is the installation of components sensitive to overheating. The melting point of the material is 142-145 degrees.

The melting point of the ROSE alloy ranges from 90 to 94 degrees. This species is labeled as POSV-50. The composition contains 25% tin, 25% lead, and 50% bismuth. The percentage of metals may vary slightly. The material is produced in the form of rods, granules, pigs.

The composition is used in jewelry production, for mounting electronic devices, and tinning copper tracks on printed circuit boards. It is used in electromechanics for protective fuses and fuse links. And also for dismantling radio-electronic components and connectors with plastic cases

Benefits of ROSE:

releases a minimal amount of toxic substances, as it does not contain cadmium;
easy to melt, contact with boiling water is sufficient;
can be used at home without the use of special equipment;
economical to use.

The melting point of the VUDA alloy is in the range of 65-72 degrees, which expands the scope of its application. But 10% of cadmium in its composition makes the material toxic. The remaining components of the alloy: 13% tin, 27% lead, 50% bismuth.

It applies:

in sensors of fire alarm systems;
in microcircuits;
in galvanoplasty;
in dentistry;
for the production of cast elements;
in typography for the production of fonts, matrices, cliches;
in mechanical engineering and shipbuilding;
in the aviation industry;
in the metallurgical industry.

Other types

There are rare solders used for special conditions. These include:

Nickel-based compounds used in parts operating at high temperatures;
gold, used for vacuum tubes;
magnesium, used in ferrous and non-ferrous metallurgy.

We will give examples of some of them, since there are a lot of them and it will not be possible to consider all types within the scope of the article.

Solder paste

Soldering microcircuits, installing SMD components on printed circuit boards, and complex repairs of mobile phones can be carried out using soldering paste consisting of no-clean flux and Sn62Pb36Ag2 alloy. The composition contains 62% tin, 36% lead and 2% silver.

The paste meets the basic requirements imposed on it by surface mount technologies (SMD components) in the electronics industry.

For aluminum

Lucas-Milhaupt Filalu 1192 NC solder has good fluidity and high adhesion to aluminum. They can be used to solder refrigeration equipment, car radiators, and air conditioners. Soldering aluminum to aluminum will not cause any difficulties even for non-professionals. Available in the form of a rod with flux inside. Melting point 577 degrees.

Composition structure: Si-11.94%, Fe-0.18%, Cu-0.01%, Mn-0.03%, Mg < 0.01%, Zn-0.01%, Al-rest, FLUS - 32%

For copper

Almost any type of copper, both soft and hard, is suitable for soldering copper. For example, you can use solders made of tin, lead, zinc, and silver.

Bottom line

A great variety of solders for soldering various products are produced; listing them in the scope of one article is simply not realistic. But to summarize what has been said above, we note:

To install radio-electronic components, radio amateurs use the relatively low-melting POS-61; parts on lead-free solder are soldered by preliminary tinning with ROSE alloy to reduce the melting point; subsequently the parts are easily dismantled. Hard-melting grades are used for pipes and refrigeration equipment.
The alloy composition should not contain toxic substances in excess of the established norm. Work should only be carried out in a ventilated area, observing safety precautions.

Related materials:

Source: https://samelectrik.ru/kakie-byvayut-pripoi-dlya-pajki-vidy-marki-naznachenie.html

Wood's alloy

This low-melting alloy of heavy metals owes its appearance and name to the American dentist Barnabas Wood, who discovered its composition in 1860. It should be noted that the very fact of obtaining a low-melting alloy was not something unique, since back in 1701 Newton obtained a similar alloy, but without the use of cadmium. Thus, Newton's alloy consisted of 50% bismuth (Bi), 31.2% lead (Pb) and 18.8% tin (Sn).

In Wood, we have about 50% Bi, about 25% Pb, and 12.5% Sn and, attention, cadmium (Cd). True, Newton's alloy has a melting point of 97 degrees Celsius, and Wood's alloy - about 67. Wood had problems with lead and tin, but apparently for some reason there were no problems with cadmium, so he replaced lead with the latter and tin. And so an alloy was obtained, which at normal temperature is in a crystalline state, but already becomes liquid in hot water

(see video).

Apparently, it was the relatively low melting point that made this alloy and its inventor so famous. After all, before this, the well-known low-melting alloys Rose (1772) and D'Arcet (1775) had a melting point of 95 degrees Celsius. A reduction in the melting point by 26% undoubtedly provided the opportunity for very significant energy savings, with all that entails, especially taking into account the areas of application of Wood's alloy.

Soldering and tinning - “wood alloy”

Among radio amateurs and electronics engineers, Voodoo alloy has found application for soldering and tinning, and here's why. Tinning, as we know, involves applying a thin layer of tin to another metal, thereby protecting the metal from oxidation and corrosion. And as we learned above, Wood's alloy is an alloy containing tin.

In addition to its fusibility, Wood's alloy has good fluidity, which allows it to spread evenly over the surface and fill the slightest cracks. In order to tinning tracks on a printed circuit board, you need: water, grains or rods of the alloy itself, citric (or soldering) acid. Tinning with Wood's alloy occurs as follows (see.

video, although it talks about the Rose alloy, but for the Wood alloy it is also suitable with a little clarification):

1. Pour water (or glycerin) into a container, heat it, measuring the temperature, bring it to the melting point temperature, i.e. about 68.5 degrees Celsius.

2. Add a little citric acid to hot (very hot, but not necessarily boiling) water.

3. Then a pre-cleaned board is placed in a container, which needs to be tinned, and several pieces of Wood’s alloy are laid out on the copper tracks of the board. The water is heated, the alloy heats up and turns into a liquid state.

4. Using a tampon, or better yet, a wooden or plastic spatula, tinning the tracks is done by rubbing drops of liquid alloy along the tracks of the board.

5. After tinning, cover the board with rosin (flux) and wash it.

The described tinning method is hot, with coating applied by rubbing. Another hot application method is immersion. But in this case, of course, an alloy bath is used, for which the required amount of raw materials is much greater than for the grinding method.

When soldering, or rather desoldering elements from boards - processors and microcircuits, connectors and other parts - Wood's alloy is good because its melting point is much lower than the melting temperature of the plastic parts' housings.

Therefore, there is no need to fear that the plastic case will be damaged during desoldering (or soldering). Of course, all soldering operations in any case must be done as carefully and carefully as possible.

This alloy can be used to solder various metals and alloys (copper, nickel, aluminum, bronze and brass), as well as products made of precious metals.

In general, Wood's alloy greatly facilitates the tinning process, which is very important for beginners in this business.

Brief characteristics of the alloy

Wood's alloy is produced in the form of silver-white round rods or droplet granules. Tensile strength is about 45 MPa, elongation 7%, Brinell hardness 10.5 units, density 9720 kg/m3. The shelf life of alloy ingots is 3 years.

Metallographic studies of the alloy show that the components of which it consists do not dissolve in each other and do not form chemical compounds. The structure of the alloy is eutectic, including light dendrites of the solid solution containing bismuth, and dark complex eutectic (containing all four components).

Where else is Wood's alloy used?

There is a wide range of applications for material with the properties of Wood's alloy. This is primarily its technological properties, which include the ability to remove the alloy with hot water. For example, an application is the method of bending pipes with thin walls, which, when bent without special means, will be deformed, i.e.

will wrinkle into at least an uneven corrugation. To prevent such deformation, the pipes inside are filled with an alloy that inhibits corrugation. Then, after bending the pipe, the alloy is easily removed, flowing out when heated.

For the same reason, the alloy is also used in electroplating, where it fills cavities in metal products.

Another technological purpose of the alloy is precision casting, i.e. such casting in which the resulting dimensions must be observed very accurately, even taking into account the heat shrinkage of the casting alloy. Wood's alloy has very low shrinkage.

The alloy is also used for scientific purposes. It is used to obtain metallographic samples when the sample itself is very small and inconvenient for grinding and polishing. Then it is filled with Wood's alloy to a size that allows processing of microsections. In addition, the alloy is known to be used in chemical laboratories to create a low-temperature heating bath.

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It is known that parts made from Wood's alloy can also be found in sensors that respond to temperature, as a rule, these are fire alarm sensors.

It is known that Wood’s alloy also traveled to space in 1976 at the Salyut-5 orbital station, where, as part of a technological experiment codenamed “Sphere,” cosmonauts B. Volynov and V. Zholobov acted as metallurgists, studying the solidification process liquid metal under zero gravity conditions.

Where can I buy wood alloy?

The fame of Wood's alloy can be assessed by where and how it can be purchased for your purposes. The alloy is so in demand that nowadays it is even sold via the Internet. It can be found on all popular e-commerce platforms - eBay, Vse Instruments.ru, Aliexpress, Alibaba. It is produced mainly by chemical factories (for example, the Ural Chemical Reagents Plant).

Application features and differences from analogues

As already noted, Wood's alloy is not the first and not the only similar alloy with a similar composition. The most famous analogue is the Rose alloy. However, the Rose alloy has a higher melting point, which is generally not critical for modern soldering technology, but requires the use of glycerin for heating. Glycerin, when heated at high temperatures, evaporates intensely and smokes.

The only significant advantage of Rose's alloy is that it is non-toxic, since it does not contain the carcinogenic toxin cadmium.

The toxicity of Wood's alloy is its main drawback, which determines the need for special safety measures, consisting of monitoring maximum permissible concentrations and organizing ventilation during operation.

Source: http://popayaem.ru/splav-vuda.html

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WATCH THE VIDEO ON THE TOPIC: Alloy Rose. Soldering, tinning, composition, application and melting point.

WOOD alloy 1pc (100g)

Dentist Barnabas Wood is working on an alloy that would have a low melting point on one side and a high density on the other. After a series of experiments, he finally managed to achieve his goal. Wood's alloy, which later received his name, met all the requirements that were initially placed on it. Then it received the widest application, going far beyond dentistry. It is supplied in the form of granules in special bags, the total weight of which does not exceed a gram.

The composition of Wood is regulated by the industry standard TU 6 09 It is immediately worth noting that there are several varieties of Wood alloys. They include the same type of elements, but have different relationships between them.

This parameter remains unchanged even when environmental conditions change, which is especially valuable in electrical engineering. Wood is a material with a high ductility value. We also note that the alloy is easily accessible to the average consumer.

Buying Wood now is not difficult.

Most electrical stores carry it in stock. But besides the advantages, Vuda has a number of disadvantages. The main one is the inability to withstand high temperatures for an extended period of time, which significantly reduces the scope of application.

The second disadvantage is the tendency to cracks. Any impact on the alloy can lead to its destruction. In this regard, handling it during operation should be extremely careful. For this reason, when working with Wood, strict adherence to safety rules and the presence of a high-quality exhaust system are necessary.

Wood serves as a material for smelting all kinds of metals in metallurgy. But among all this variety of uses, the main purpose of the alloy is still its use as a solder for soldering. The peculiarity of soldering with Wood alloys is the use of low-power soldering irons. This way we reduce the risk of metal overheating and prevent alloys from losing their viscosity properties.

Copious amounts of solder do not guarantee a higher quality connection. When soldering with Wood's alloy, the accuracy of the movement during its application is of greater importance. This will prevent unwanted elements such as oxygen, hydrogen and other gases contained in the atmosphere from entering the alloy.

Thus, the presence of flux contributes to better quality and adhesion of the solder. After soldering, it is necessary to give time for the alloy to crystallize. But even after this, it is not recommended to subject the microcircuit to mechanical stress due to the high fragility of the alloy. To control the quality of soldering, visual inspection is sufficient. Updated February 02 Applications Wood alloy has many uses in technical production.

Source: https://all-audio.pro/c25/obzori/splav-vuda-toksichnost.php

Wood's alloy: characteristics and composition

America. 1960 Dentist Barnabas Wood is working on an alloy that would have a low melting point on one side and a high density on the other. After a series of experiments, he finally managed to achieve his goal. Wood's alloy, which later received his name, met all the requirements that were initially placed on it. Then it received the widest application, going far beyond dentistry.

General information

Wood's alloy is a bismuth-based chemical compound and has a gray-black color and a metallic luster. It is supplied in the form of granules in special bags, the total weight of which does not exceed 100 grams.

Wood's composition is regulated by industry standard TU 6 09 4064-87. According to the specifications, it includes the following elements:

Tin – 12%.
Cadmium – 12.5%.
Lead – 20%.
Bismuth – 50%.

It’s worth noting right away that there are several varieties of Wood alloys. They include the same type of elements, but have different relationships between them.

Features and Specifications

The main feature of Wood is its low melting point, which is about 72 ºC. This parameter remains unchanged even when environmental conditions change, which is especially valuable in electrical engineering.

The second feature is the relatively high density value. It is equal to 9720 kg/m3, which is approximately 20% higher than that of structural steel. Wood's alloy has one of the highest densities compared to other types of solders, the melting point of which does not exceed 100 ºC.

Wood is a material with a high ductility value. The relative elongation is 40%, and the relative contraction is 60%.

We also note that the alloy is easily accessible to the average consumer. Buying Wood now is not difficult. Most electrical stores carry it in stock.

But besides the advantages, Vuda has a number of disadvantages. The main one is the inability to withstand high temperatures for an extended period of time, which significantly reduces the scope of application.

The second disadvantage is the tendency for cracks to form. Any impact on the alloy can lead to its destruction. In this regard, handling it during operation should be extremely careful.

It is also worth noting the increased toxicity of the material due to the presence of cadmium in its composition. For this reason, when working with Wood, strict adherence to safety rules and the presence of a high-quality exhaust system are necessary.

Application

Wood's alloy has many uses in technical manufacturing. It can be found in both high-precision casting and electroplating. It is used to tinning printed circuit boards and is used as a reagent in the chemical industry. Wood serves as a material for smelting all kinds of metals in metallurgy. But among all this variety of uses, the main purpose of the alloy is still its use as a solder for soldering.

The peculiarity of soldering with Wood alloys is the use of low-power soldering irons. This way we reduce the risk of metal overheating and prevent alloys from losing their viscosity properties.

To avoid waste of material when soldering small parts, you should use a soldering iron with a thin and flat tip. Copious amounts of solder do not guarantee a higher quality connection. When soldering with Wood's alloy, the accuracy of the movement during its application is of greater importance.

Also, when soldering, it is necessary to use flux, even though the material has a low melting point. This will prevent unwanted elements such as oxygen, hydrogen and other gases contained in the atmosphere from entering the alloy. Thus, the presence of flux contributes to better quality and adhesion of the solder.

After soldering, it is necessary to give time for the alloy to crystallize. But even after this, it is not recommended to subject the microcircuit to mechanical stress due to the high fragility of the alloy. To control the quality of soldering, visual inspection is sufficient.

Source: https://prompriem.ru/stati/splav-vuda.html

Characteristics and composition of Wood's alloy

Wood's alloy is a material that is used in soldering radio components, electroplating, and working with chemicals in laboratories. For people interested in studying homogeneous metals and alloys, it would be a good idea to study this material in more detail.

History of discovery

The low-melting alloy was first discovered by the American dentist Barnobas Wood. This event took place in 1860. However, in 1701, Newton discovered a similar material, which differs from Wood in the absence of cadmium in the composition. The melting point of the material discovered by the American is 67 degrees. Newton's mixture melts at 97 degrees.

What is Wood's alloy?

It is a fusible material made from heavy metals.
It is available in the form of silver-colored rods or granules, which are used in various fields of production. The mixture does not require special conditions for storage and transportation. Galileo. Experiment. Wood's alloy

Compound

The technical characteristics and properties of the material depend on its composition. The main components of the composition must be contained in a certain amount:

tin - 12.5%;
bismuth - 50%;
cadmium - 12.5%;
lead - 20%.

The melting point varies depending on the content of components in the composition. Changes are minor from 60 to 70 degrees.

Individually, the components have a high melting point. However, when the composition changes, this figure decreases. To improve ductility, the percentage of cadmium is increased to 20%.

Specifications

The mixture is unique in its characteristics, which depend on the components included in its composition. Technical specifications:

Melting point is 60–70 degrees.
Density - 9720 kg/m2.
High ductility index.

Due to its characteristics and composition, the mixture interacts with various metals. Compared to other materials used for soldering, this mixture of metals has a high density.

Soldering with low temperature soldering iron

Advantages

The alloy has a number of advantages:

The low melting point allows the mixture to be used for joining parts sensitive to high temperatures.
No powerful equipment is required for heating.
When used in technical and chemical fields, the mixture is considered indispensable.
High density.

You can purchase granules and rods from Wood's mixture at any hardware store.

Flaws

In addition to the advantages, the material has disadvantages:

cannot withstand high temperatures;
breaks down under high mechanical loads.

Wood's alloy is considered a unique material that is used in the chemical and technical industries. Thanks to the components of the composition, the mixture has certain characteristics that make it unique. It is important to understand that it cannot be used at high temperatures and heavy loads.

Source: https://metalloy.ru/splavy/vuda

Toxicity[ | ]

Wood's alloy is toxic due to its cadmium content, so contact with bare skin is considered harmful, especially when molten. It is known that vapors from cadmium alloys pose a danger to humans. Cadmium poisoning carries a risk of cancer, anosmia (loss of smell) and damage to the liver, kidneys, nerves, bones and respiratory system.

Dust can form flammable mixtures with air.

Application[ | ]

Wood's alloy is used in precision casting, in bending operations of thin-walled pipes, as lost melt rods in the manufacture of hollow bodies by electroforming, for pouring metallographic sections, in fire alarm system sensors, as a low-temperature heating bath in chemical laboratories, etc.

Common mistakes[ | ]

Due to the origin of the surname Wood from the English. wood (forest, wood), inexperienced technical translators sometimes call the alloy “wooden metal”.

The invention of the alloy is often attributed to the American physicist Robert Williams Wood, especially since a prank using the alloy is mentioned in W. Seabrook’s biographical book about him, but the famous physicist was born only in 1868, 8 years after this invention, and, moreover, even is not a relative of the inventor of the alloy, Barnabas Wood.

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Literature[ | ]

Chemical dictionary for a schoolchild / B. N. Kochergin, L. Ya. Gornostaeva, V. M. Makarevsky, O. S. Aranskaya. - Mn.: Narodnaya Asveta, 1990. - P. 45. - 255 p. — 75,000 copies. — ISBN 5-341-00127-3.

Links[ | ]

Source: https://encyclopaedia.bid/%D0%B2%D0%B8%D0%BA%D0%B8%D0%BF%D0%B5%D0%B4%D0%B8%D1%8F/%D0% A1%D0%BF%D0%BB%D0%B0%D0%B2_%D0%92%D1%83%D0%B4%D0%B0

Quinoa: what kind of grain, how to cook, what is useful?

Today in the store my eyes fell on a new product. It became interesting: quinoa cereal - what is it, and why is it so good that for 300 gamma you need to pay 170 rubles?

Packets with small grains were hidden behind more “serious” cereals - rice, chickpeas and buckwheat. They looked modest, and the price tag was hefty. Still, I decided to take it for a test and did not regret it. The grains contain enormous healing power. Their taste (or rather, its almost complete absence) creates great scope for imagination and culinary experiments.

What does the word quinoa mean?

The word is unusual and does not sound Russian. Not surprising given its South American origins. It is often translated as "rice quinoa." Sometimes the name sounds like quinoa or quinoa. It refers to a grain crop that originally grew on the slopes of the Andes.

Quinoa is a herbaceous plant 1-3 meters high. It has very ancient origins. Its closest “relatives” are spinach, beets, and also quinoa, widely known in our area.

Quinoa fruits are miniature seeds ranging in size from 1.5 to 4 mm. Shade - from light to dark brown. I got the light ones. They cook faster than other varieties, of which there are about 120.

The Incas grew quinoa more than 7 thousand years ago. They considered the product a sacred gift of the gods and called it “golden grain.” Together with corn and potatoes, it formed the basis of their diet. The plant had great religious significance. It was used during ceremonies and revered as a shrine.

The Spanish conquerors destroyed the fields and replaced the crop with wheat. The plant has survived only in hard-to-reach high mountain areas. Only by the beginning of the 21st century was quinoa appreciated. This happened due to the revival of interest in natural foods.

Today the culture is gradually spreading to all parts of the world. Its production (as well as consumption) is growing every year. Only three countries supply it to the world market: Peru, Bolivia, and Ecuador. Perhaps this is precisely the reason for the high price, which initially puzzled me.

Quinoa ripens even in extreme conditions. It bears fruit at altitudes of up to 4000 meters and easily tolerates drought and sudden temperature changes. In addition, it is incredibly productive. It’s hard to believe, but a glass of seeds will yield a harvest of 600 kg to a ton!

This is probably why the UN declared 2013 the International Year of Quinoa. Speaking at the 66th session of the UN General Assembly, Secretary General Ban Ki-moon emphasized the importance of the product for global food security.

Quinoa: calories , composition

Cereals are considered one of the most valuable products in the world. It contains more protein than buckwheat, barley or oatmeal. In some varieties its percentage reaches 19-20. The fruits contain enough isoleucine, which is low in other grains.

There is a complete set of essential amino acids. The compounds are not produced by the body, but without them it cannot function normally.

Quinoa proteins have high biological value. They are easily digestible and are not inferior to animal proteins.

Calorie content of 100 grams is 368 kcal, which is almost a third of the daily requirement. We are talking about raw grains.

The fruits have relatively few fatty acids. The ratio of omega-6 to omega-3 is about 6, which is close to optimal.

Popular couscous, “good old” semolina or pearl barley were not even close to quinoa in terms of vitamin composition. Unless chickpeas will compete with it.

Vitamin data is presented below.

Name	Amount per 100 grams, mg	% daily requirement
B1	0,36	24
B2	0,318	17,7
choline	70,2	14
B5	0,772	15,4
B6	0,487	24,4
B9	184	46
E	2,44	16,3
PP	1,52	7,6

Quinoa contains twice the protein, fiber and potassium of oatmeal. Carbohydrates – 57.2 grams per 100 g. All of them are very healthy. Their glycemic index ranges between 35 and 53. This means that they help control weight and normalize lipid and sugar levels.

Another benefit is dietary fiber. There are 11-16% of them here. They remove “bad” cholesterol and prevent the risk of cardiovascular diseases and hemorrhoids.

Mineral composition

In terms of phosphorus, quinoa is not inferior to many types of fish, and in terms of iron it is twice as high as wheat. Magnesium is three times more than in dried apricots or dried figs. A serving of porridge will cover half the daily requirement.

The only thing I couldn't find was silicon. The USDA National Nutrient Database for Standard Reference does not list this critical chemical in quinoa.

I put the data on micro- and macroelements in a table.

Name	Amount in 100 grams, mg	% of norm
Potassium	563	22,5
Calcium	47	4,7
Magnesium	197	49,3
Sulfur	141,2	14,1
Phosphorus	457	57,1
Iron	4,57	25,4
Manganese	2,03	101,7
Copper	59	59
Selenium	0.85	15,5
Zinc	3,1	25,8

As you can see, quinoa is one of the few foods that contains a significant proportion of selenium. The element resists tumor growth and reduces inflammatory stress. It is necessary for the proper functioning of the endocrine system.

Scientists have discovered 23 polyphenolic compounds in cereals. The substances have strong antioxidant properties. The leaders among them are ferulic acid and quercetin.

Another beneficial compound is betaine. It gets rid of fat deposits and promotes muscle gain. The substance regulates fluid balance in cells, improves appearance and heart health. A more accessible source of betaine is beets.

Quinoa does not contain gluten. For me with my AIT this is a big plus. Protein causes an autoimmune reaction in many people. So it’s not in cereals. This makes it an ideal food for celiac disease sufferers. Feel free to include the product in gluten-free diets.

Quinoa cereal: beneficial properties and contraindications

Cereal porridge saturates the body with nutrients and improves health. It is suitable for allergy sufferers and diabetics.

The healing power of quinoa is still under study. It is known that it contains biologically active substances with antioxidant activity. They neutralize free radicals that destroy cells at the molecular level.

Quinoa has a number of other healing properties:

Strengthens health and gives strength. B vitamins normalize the functioning of the nervous system and help cope with emotional stress.
Improves appearance. A serving of porridge provides a quarter of the daily requirement of pyridoxine. It is responsible for beautiful nails, healthy hair, elastic skin.
Reduces the risk of diabetes. Manganese regulates glucose levels. Experiments on rats conducted in 2013 at the Veterans Affairs Medical Center (Salt Lake City, USA) showed that consuming quinoa reduces sugar and cholesterol levels.
Quinoa is a valuable source of potassium and magnesium. The elements are important for the proper functioning of the heart. They normalize blood pressure and reduce the risk of stroke and heart attack.
The high percentage of calcium makes “golden grains” a good substitute for dairy products. This can make life easier for those who are lactose intolerant.
Supports bone health. Due to its high content of magnesium, phosphorus and manganese, quinoa prevents osteoporosis.
Like flaxseed, the product is rich in alpha-linoleic acid. This type of omega-3 fatty acids reduces the risk of arrhythmias, thrombosis, high blood pressure and inflammation of the vascular walls.

The product accelerates metabolism and activates the breakdown of fats. It helps to get rid of excess weight and improve your figure.

Contraindications and possible harm

The main disadvantage of quinoa is the presence of triterpene saponins. They protect the plant and are harmful to humans. Organic compounds give the taste a bitter tint and can destroy red blood cells.

It is easy to get rid of them by soaking, but this is not necessary. Breeders have developed cultivated varieties with low saponin content. During the production of cereals, the shell where they are concentrated is removed.

Another undesirable substance is phytic acid. It binds iron, zinc and other minerals, preventing their absorption. Heat treatment and soaking reduce the concentration of the antinutrient.

Sometimes pre-soaked quinoa is available on sale. This makes further processing easier.

The product rarely causes an allergic reaction. Only one such case is described in the literature. If you have never tasted Eliquinoa, be careful when you taste it for the first time. Don't forget about the risk of individual intolerance.

Nutritionists do not recommend eating a lot of quinoa for those who have oxalates in their urine, as well as for nursing mothers and pregnant women. It should not be given to children without the permission of the pediatrician.

How long to cook quinoa, how to cook it?

The cereal cooks quickly. This will take from 10 to 20 minutes, depending on the variety. Usually the volume increases 3-4 times. Boiled cereal will stand in the cold for a week.

How to cook quinoa - procedure:

Place measured amount into a small saucepan. One partial glass is enough for 3 servings.
Rinse.
Pour cold water over the cereal.
Let stand for at least 30 minutes. If desired, leave overnight in a cool place. This will remove the bitter taste.
Rinse, fill with water in a ratio of 1 to 2.
Bring to a boil.
Cover with a lid.
Keep on low heat for 15 minutes.
Set aside and let it swell.
When serving, drizzle with butter.

I deliberately skipped the “Salt” point. Cereals are useful for potassium, which removes excess fluid from the body. Sodium is its antagonist. I try not to salt such valuable products at all, but add spices for taste.

Boiled seeds have virtually no taste. They reminded me of rice. It is the perfect base or addition to any dish. The cereal can be a side dish, an ingredient in a salad, appetizer or soup.

It is served with meat, poultry, and seafood. The cereal goes well with apples, pears, blackberries and other berries. The hot dish is in harmony with vegetables: eggplants, zucchini, carrots and green peas. Spices will complement the taste:

caraway,
garlic,
onion,
turmeric,
rosemary,
basil.

I have seen recommendations to calcinate the cereal before cooking in a dry frying pan. I don't see the need for this. The taste is not neutral. If desired, it can be easily given any shade, and excess heat treatment will reduce the nutritional value.

Conclusion

I will tell you more about other interesting recipes in one of the following articles. For now, let's summarize:

adding quinoa to the menu helps you lose weight,
stabilizes blood sugar levels,
protects against diseases,
improves heart health,
gives slimness,
strengthens bones.

Quinoa is not very popular in Russia yet. It's a pity. It can become an important component of a gluten-free diet, saturate the body with valuable substances, and protect against diseases. Look for it in the cereal aisle. It is much healthier than the fashionable “paste”.

I hope I was able to talk in detail and interestingly about quinoa grains: what it is, how to cook it, how it is useful. If you're in a large supermarket, take a closer look. What if an exotic guest from South America has already appeared in your city?

Source: https://100polezno.ru/pprodukty/krupy-i-bobovye/kinoa-krupa.html

Translation - chemical or physical treatment to determine the structure - - to english

781 bunker (metallurgy) bunker Capacity for storing bulk and lump materials (ore, concentrates, metallized pellets, etc.), unloaded at the bottom through a gate or disc feeder. For unloading by gravity the lower part b. They are made with inclined walls in the form of an inverted truncated pyramid or cone. B b. large capacity (usually square section) install partitions to reduce the lateral pressure of the load. material on the walls and facilitate unloading. [http://metaltrade.ru/abc/a.htm]

EN

Russian-English dictionary of normative and technical terminology > bunker (metallurgy)

782 buffer (memory area)

Russian-English dictionary of normative and technical terminology > buffer (memory area)

783 bush hammer

bush hammer A hand tool or hand machine for decorative processing of stone, concrete and plaster surfaces using a special attachment

[Terminological dictionary of construction in 12 languages (VNIIIS Gosstroy USSR)]

FR

boucharde
marteau a boucharder

Russian-English dictionary of technical terminology > bush hammer

784 bunker car

bunker car A freight car with a covered bunker-type body, equipped with a pneumatic unloading or tipping system, intended for the transportation of bulk and powdery cargo that requires protection from atmospheric influences

[Terminological dictionary of construction in 12 languages (VNIIIS Gosstroy USSR)]

Wood's alloy and its positive aspects

1. The lowest melting point of an alloy is less than 100 degrees Celsius. That is why it is perfect for soldering small parts that are very sensitive to high temperatures. Tools for this are suitable even with low power.

2. The composition is more than affordable, therefore it is widespread.

3. Its application in many fields is a necessity.

4. The material has a fairly high density.

Negative aspects of Wood's alloy

It is not recommended to use at high temperatures, so even at home it is not always suitable for use.

Characteristics

The material is fusible and incredibly plastic. Able to react with almost all metals and surfaces. For its low melting point, compared to other metals, it is considered one of the most dense.

THIS IS INTERESTING: How to make stainless steel

Soldering and its features

Important! Solder melts at very low temperatures, so all other features must be taken into account.

Wood's alloy is very often used in chemical type operations and in narrow technical fields. However, in most cases it is still used when soldering materials. Melting at low temperatures ensures the use of low-power soldering irons and other equipment. Care should be taken to ensure that overheating does not occur and that the composition remains viscous at all times, because it is in this state that it solders most reliably.

For use when working with small parts, you need to use a flat tool tip to save material consumption. When using a large amount of solder, it is impossible to guarantee a truly stable and high-quality connection, because accuracy is much more required here.

Otherwise, it may happen that the soldering area simply blurs, and the extra parts are completely wrong where they should be. Then you will have to use numerous methods to get rid of material from the board. And this will take a huge amount of time and effort.

Therefore, it is recommended to use only small proportions at once.

Wood's alloy, regardless of its low melting point, is recommended for use with low-melting materials. The connection will be of higher quality and will also ensure that there are no problems when soldering materials. However, the material is often used for tinning, in which exposure to high temperatures is necessary. The parts adhere much better, and a high-power soldering iron quickly liquefies the alloy.

It is necessary to be careful, speed and accuracy when soldering parts, because the material hardens quite quickly. When applied to the surface, you should not check it later, because the result may turn out to be weaker than expected. Wood's alloy is a fairly fragile material, so it is worth protecting it from physical impact and simply inspecting it visually.

Source: https://svarkagid.com/splav-vuda/

Wood's alloy - about production

This substance is named after its creator: B. Wood developed it back in 1960. The material is a low-melting material that already exhibits fusible properties at temperatures from 68.5 to 75 degrees. To make Wood's alloy, well-known materials are used: lead, cadmium, tin, bismuth and others.

At the same time, their percentage in the product is different. Thanks to the special production technology of Wood's alloy, high strength is achieved (tensile strength - 4.5 kgf/kW.m.) If you try to stretch the product, its length can increase by 7%.

All these properties of the material allow it to be in demand in a wide variety of industries.

Wood's alloy - about appearance

Externally, Wood's alloy consists of silver-white rods. It can also be produced in granules. The form is selected depending on the scope of its use, as well as the technology used in the production of the product.

About application

Wood's alloy is often used when it is necessary to make a cavity in a metal product. Wood's alloy is actively used in industry for flexible thin-walled pipes. It is also used for tinning boards that are used in radio engineering and electronics.

The product is successfully used in the manufacture of plugs, inserts and other elements of various sizes and designs that are used in safety devices. Thanks to Wood's alloy, it is possible to carry out the process of soldering copper and non-metal products.

The unique properties of Wood's alloy allow it to be used in a wide variety of production areas.

Wood's alloy - transportation

If you follow safety rules, this product can be transported using a variety of vehicles. And this allows it to be delivered to any corner of the country. Transportation safety must be ensured when transported by any type of transport.

Wood's alloy - about storage

To preserve the properties of this substance, it should be kept in a special container in a room with good ventilation.

Wood alloy - about safety precautions

Before you start work, you should know and follow the safety regulations that apply to operations with toxic compounds. It is important that all work with the material is carried out in a well-ventilated area, close to an exhaust hood. Only in this case the exposure to toxic substances will be minimal.

Wood's alloy - about the impact on humans

Wood's alloy is highly toxic, as a result of which its negative effect on humans is obvious. That is why it is so important to follow the rules of use with this reagent to prevent toxic effects. First of all, a good ventilation system is necessary. Long-term work is not recommended. In this case, vomiting, dizziness, pain, etc. may occur.

Editor: nfj4w6

Source: http://www.upcr.ru/news/splav_vuda/

Wood's alloy structure

Since this site is devoted to metallography, it is natural that here we are interested in the use of Wood's alloy in metallographic preparation , i.e. sample preparation. How is it used and what is its structure?

Wood's alloy is presented on many websites on the Internet. As a rule, the information on them is repeated. The composition, physical properties, history of creation are given. Its low melting point is noted. Other low-melting alloys are mentioned here.

According to Wikipedia, Wood's alloy is a heavy fusible alloy, invented in 1860 by the English engineer Barnabas Wood. Melting point 68.5 °C, density 9720 kg/m³. Composition (wt.%): tin - 12.5; lead - 25; bismuth - 50; cadmium - 12.5.

It is used in precision casting, in bending operations of thin-walled pipes, as lost-wax rods in the manufacture of hollow bodies by electroforming, for pouring metallographic sections , in fire alarm system sensors, as a low-temperature heating bath in chemical laboratories, etc.

The metallographic applications and structure of Wood's alloy are little discussed on the Internet. There are no illustrations either.

Application of Wood's alloy in sample preparation

For metallographic examination it is necessary to make a thin section, i.e. the surface of the sample, which is viewed through the microscope, must be a mirror. If the sample is large enough, processing it is not a problem. After cutting, it is cleaned on a grinding wheel, then using sandpapers, pastes and finally polished. This results in a mirror surface.

But what to do if you need to see, for example, the structure of a wire in cross section, or a thin (several micrometers) layer on a cross-section of a sample, or the structure of a metal powder? You can't just polish it like that. The wire will bend if you apply force during processing, the powder must somehow be converted into a compact material, and the thin layer will “collapse”, i.e.

will not be flat, but will turn into a rounded shape and will not be visible through a microscope. This is shown in Figure 1.

Figure 1. Sample edge collapse; 1 - edge of the sample, which is below the focus; 2 - area in focus; 3 - area located above the focus; 2000s

Therefore, the sample area must be artificially increased. To do this, a mandrel (a ring about 1 cm high) is placed on a copper plate, a sample is placed inside it, and the free space is filled with molten Wood’s alloy.

Since its melting point is low, the structure of the sample will not change as a result. If the sample is a low-melting alloy, then instead of Wood's alloy, plastics or epoxy resin are used, which harden at room temperature.

An example of filling a sample with Wood's alloy and plastic is shown in Figure 2. With this method of preparing a thin section, the edge of the sample will be clearly visible.

Figure 2. Sample embedded in Wood's alloy (a), plastic (b).

A sample made with filling will also be “in sharpness” over the entire surface (Fig. 3).

Figure 3. Sample prepared with Wood's alloy casting (carbon steel, compression plasma treatment ); 2000s

Structure

What is Wood's alloy from a metallographic point of view ? First of all, it should be said that it consists of components that do not actively dissolve in each other at room temperature, and also do not form chemical compounds. What's even more remarkable is that all binary phase diagrams of these components contain eutectics. The structure of Wood's alloy is shown in Figure 4. It represents a typical casting structure: light solid solution dendrites and complex eutectic.

Figure 4. “Fresh” Wood’s alloy (a) and used one after repeated remelting and pouring of thin sections (b).

Phase and chemical composition of Wood's alloy

X-ray data confirm that there are no chemical compounds between the components in Wood's alloy. The X-ray image contains interference lines of the metals that make up the alloy. Below is an X-ray diffraction pattern of Wood's alloy, taken on a DRON-3 diffractometer using copper radiation, as well as the results of its interpretation.

Figure 5. X-ray diffraction pattern of Wood's alloy .

Scanning electron microscopy (SEM) can be used to determine which elements are present in an alloy. In this case, you can install the composition at a certain point on the surface. Below is shown the composition of the alloy in two areas - in the light (in a scanning microscope it looks light gray) and in the dark. In the light area, only bismuth was detected. There is 50% of it in the alloy, which means the light dendrites are bismuth. All 4 elements that make up the alloy were found in the dark areas.

Figure 6. Wood's alloy composition in the light area (marked with a red marker).

Figure 7. Wood's alloy composition in the eutectic region.

The structure of Wood's alloy looks interesting after repeated use? Such an alloy is contaminated, so it is difficult to say what exactly its composition is (and there is no need!). But you need to know what it looks like. Since the alloy is cast, it contains dendrites. The light dendrite may be bismuth. Dark - possibly lead-based, but we can say for sure only after elemental analysis.

A	b
V	G

Figure 8. Dendrites in “dirty” Wood’s alloy : a - bright field, b, c, d - differential interference contrast.

Source: http://structure.by/index.php/studentam/o-metallakh-i-nemetallakh/56-struktura-splava-vuda

Composition and properties

Wood's alloy consists of a mixture of metals - bismuth, lead, tin and cadmium. From 50 to 50.4% in the alloy - the share of bismuth, lead - from 24.9 to 25.1%, tin - 12.5 - 14.3% and cadmium - 10.2 - 12.5%. Wood's alloy is a low-melting alloy, that is, its melting point is less than 70 degrees, it is a casting alloy, its density is 9,720 kg / cubic meter. m. The melting point depends on the percentage of components and is 60 - 68.5 degrees Celsius.

Wood's alloy is silver-white in color with a metallic sheen; a crystalline (granular) structure is visible at the fracture. Each individual component of the alloy has a high melting point, but it is precisely this percentage ratio that ensures such a low melting point.

In the CIS, Wood's alloy is produced according to the technical specifications of 1987, and has a lower bismuth content (40-41%). When hardening, low-melting alloys shrink, and this bismuth content allows the alloy to retain its original volume after hardening. The alloy has a high cadmium content - about 20%, which gives the alloy ductility and fusibility.

An increased content of tin in the alloy leads to a decrease in the melting point.

The industry produces Wood's alloy in the form of ingots, rods (rods measuring 10x12x250 mm), ingots and granules. Can be stored for no more than 3 years.

Where is it used?

Wood's alloy has a fairly wide range of applications. Low-melting locks made of Wood's alloy are used in automatic fire extinguishing sprinkler systems. When the air temperature rises to 70*, the lock melts and sprayed water begins to flow from the sprinkler to extinguish the fire.

Radio enthusiasts use Wood's alloy for tinning conductive paths on boards. This alloy is used as a soft solder for soldering copper parts and non-metallic parts with silver, tin - lead, bismuth - tin coatings applied by electrolysis. In electrical engineering, Wood's alloy is used when soldering some printed circuit boards, where high temperatures are unacceptable.

In industry, Wood's alloy is indispensable in the manufacture of hollow forms, as well as for imparting the desired bend to thin-walled pipes. Sometimes Wood's alloy is used in printing, where cliches, matrices and fonts are made from it.

One of the most popular low-melting alloys - Wood's alloy - is used in dental prosthetics; dies and counter-dies are cast from it in the manufacture of dental crowns and cast elements of dentures. Mouth guards are cast from the alloy to fix jaw fractures. After numerous remeltings, the alloy becomes brittle, so prosthetic dentistry has become an active consumer of this material.

Wood's alloy has another remarkable property - fluidity; it easily fills even the smallest space. This property is actively used in modeling, for example, in the manufacture of some parts of ships, airplanes, and cars.

Particular attention should be paid to safety when working with Wood's alloy. Lead and cadmium are toxic substances, so all work should be carried out with good ventilation. Production requires strict control over the concentration of these metals in process water and air.

Source: http://solo-project.com/articles/10/splav-vuda.html