At what temperature does aluminum melt - Metalist's Handbook
Aluminum is a very common metal in both industry and households. It is not uncommon that when a part breaks, there is a need to smelt a replacement. Melting aluminum at home is attractive because it is possible at a relatively low temperature. To carry out the operation yourself, you need to know the characteristics of the metal when exposed to temperature and its physicochemical properties.
Characteristics
The melting point of aluminum always depends on how pure the metal is. On average it is 660 degrees, with a boiling point of 2500 degrees.
Lightness and plasticity allow it to be perfectly processed by various technological operations.
At normal and elevated temperatures, metal actively interacts with oxygen from the air. In this case, the surface is covered with an oxide film, which serves as protection from further oxidative processes. This must be taken into account, since during melting the composition and structure of the alloy changes noticeably.
Another important characteristic is that sudden cooling can lead to internal stresses and shrinkage of the resulting metal.
Features of the technological process
By and large, remelting aluminum at home should simulate industrial casting. Raw materials prepared for melting must be cleaned of dirt, foreign impurities and possible fillers. Large workpieces must be crushed to the required size.
Casting technology involves performing several operations. During preparation, the scrap is melted in a convenient way. After achieving fluidity, it is necessary to remove the slag from the surface of the melt. The final stage is filling the prepared mold with the molten composition. Disposable forms are broken down as they cool.
At the preliminary stage, it is necessary to decide what is to be melted and what should be obtained. Even if the aluminum alloy is to be melted as an experiment, some form must be prepared. Due to this, you can evaluate the result. The ingot will show its appearance, degree of porosity and purity. Any experiment can be beneficial.
What heat source should I use?
To smelt aluminum at home you can use:
- Homemade muffle furnace. A fairly effective method that allows you to easily melt aluminum.
- An ordinary homemade oven. The natural gas temperature will be sufficient for smelting.
- Gas burner/stove or blowtorch. A completely acceptable method for small volumes of melting.
- A torch or acetylene generator, if available, can also provide the required temperature.
Using a homemade smelting furnace
The easiest way is to lay several fire bricks in the shape of a hearth. It is convenient to use a metal container as a frame. A hole should be made on the side to connect the air supply tube. A suitable metal pipe will do. You need to connect a vacuum cleaner, hair dryer or other device that supplies air to it.
Charcoal is placed in the hearth, the fire is lit and air is supplied. The container in which the aluminum will be melted is placed in the furnace. It is also necessary to line the sides with coal. The best option would be to create a lid so as not to waste heat. You can only make a passage for smoke.
Application of kitchen stove
For piece melting it is not necessary to create your own stove. You can reach the required temperature even using household gas. Given the mass of aluminum blanks for melting, the procedure itself will not take more than 0.5 hours.
You can take any suitable container, for example a tin can. It houses crushed and cleaned aluminum. However, it will not be possible to melt aluminum simply by putting a jar on fire; the required temperature is not reached. To preserve heat, the following scheme has been invented.
A jar with a crowbar is placed inside another, larger one, on supports so that a gap of up to 10 mm is maintained. In a larger jar, 30-40 mm holes are prepared in order for the flame to fit. In this case, there is no need to remove the burner divider.
The resulting structure is installed above the burner. The burning flame will pass into the inside of the larger jar and heat the container with the metal. In this case, a large tin will act as a kind of shell that retains heat. a suitable lid is placed, but a gap is left so that combustion products escape. When heating, the intensity of the flame must be adjusted.
Using the crucible and auxiliary equipment
The previous method is good, but the jar cannot withstand more than one use and may burn out. In this case, there is a risk of metal spilling onto the burner.
To work in the furnace several times, it is recommended to prepare a special container - a crucible. It is made of steel. It is quite possible to use a piece of pipe whose bottom is welded. A good device can be obtained if you use a cut-off fire extinguisher or a small oxygen cylinder with an oval profile. In this case, it is worthwhile to provide for the presence of a side chute for draining molten aluminum.
This may require auxiliary equipment, such as pliers. The ideal case would be to use side clamps and lower fixed stops - analogues of industrial installations. You will also need a long spoon to skim off the slag.
How to make a casting mold
The main tasks when melting aluminum include preparing the mold in which the liquid metal will be placed. The melt can be poured in various ways, but the main ones are open and closed casting forms.
Open method
The simplest option is to pour molten aluminum into an existing container, for example, a tin can. After the metal hardens, the ingot is removed. To facilitate removal from a form that has not yet completely cooled down, it is necessary to tap slowly.
If you don’t need a specific clear shape, you can simply pour the liquid alloy onto a non-flammable surface.
Closed method
If it is intended to produce more complex shapes or ingots, then first of all a mold must be produced that meets all the characteristics of the part. To ensure greater accuracy, it is made of several components.
Materials used for molds
If an open method is assumed, then the simplest ingredient that can always be found is mainly used - silica. The soil must be laid using layer-by-layer compaction. A mock-up mold is placed between the layers, leaving an imprint after compaction. This model is subsequently removed and molten metal is poured in its place.
In some cases, river sand is used to create forms, to which liquid glass is added. Less commonly, cement mixture and brake fluid.
When it is necessary to create a model with a complex configuration, plaster is often used. However, it can mainly be used once. When aluminum is cast into a plaster mold, a paraffin or foam blank can serve as a model.
When using paraffin, the workpiece is immersed in plaster. In this case, it is necessary to leave a small hole into which the wax is poured after the mold hardens and reheats.
If foam plastic is supposed to be used, then it is poured inside a plaster mold, in which it remains until it hardens. Subsequently, liquid metal is poured directly onto it. Due to the temperature, it melts and evaporates, and the vacated cavity is occupied by aluminum. In this case, it is necessary to take into account that the work should be carried out in a well-ventilated area or in the open air, since evaporated foam vapors are harmful to health.
Common mistakes and how to avoid them
- The plaster mold is very convenient for casting the required configuration, but plaster is sensitive to moisture. If the mold is dried in the usual way, it may remain in the composition, which reduces the quality of the casting, as it contributes to the formation of bubbles and potholes. For this reason, drying must be carried out over several days.
- The temperature of the molten aluminum must be sufficient so that it has time to fill the entire space of the mold before it begins to solidify. Therefore, after melting, you should not hesitate to pour it.
- It is not advisable to immerse molded metal in water to speed up the solidification process. This leads to disruption of the aluminum structure and cracks.
How to clean aluminum until it shines
Security measures
The operating technology involves the use of an open flame, which leads to certain limitations. Before starting work, it is worth preparing fire extinguishing equipment, checking the functionality and serviceability of gas equipment and ventilation.
Handling molten aluminum is dangerous. Therefore, work should be carried out taking into account safety precautions. It is imperative to use special clothing, eye and respiratory protection.
The following videos will show the necessary instructions and help you understand step-by-step algorithms for actions and operations with molten metal.
Source: https://ssk2121.com/pri-kakoy-temperature-plavitsya-alyuminiy/
Melting point of duralumin aluminum
Melting point is the temperature at which a crystalline solid undergoes a transition to a liquid state and vice versa.
Melting point of duralumin = 650 C (degrees Celsius).
The melting point can change significantly even from a small change in composition. See a detailed table of the melting points of various substances and materials.
This page provides basic, simple information about the melting point of duralumin. For the exact melting temperature depending on composition and pressure, see specialized reference literature. In our design organization you can order a calculation of the melting temperature of any material.
A metal such as aluminum is very common in the world. A considerable amount of it is contained in the human body, and there is even more of it in the surrounding world. Among the materials from which houses are built, as well as in the design of any car, there is a certain amount of aluminum.
Furniture parts are often made from this substance. And if suddenly one of these breaks, then you can either purchase a new product in the appropriate store, or repair the product yourself. In the latter case, you will have to melt the metal at home, and for this you already need to know about some of the properties of this metal.
To manufacture any aluminum structure, it is not at all necessary to study in detail all the characteristics of the substance, but you should pay attention to the main points, including knowing at what temperature aluminum melts.
About the melting point
It must be remembered: aluminum is very easy to cast and begins to turn into a liquid substance already at a temperature of 660 degrees. In order to understand that this indicator is quite low, it is enough to compare it with the melting temperatures of other metals, which are also often used to make certain items needed in everyday life.
For example:
- steel begins to melt only at a temperature of 1300 degrees;
- cast iron - at 1100 degrees.
But still, although the melting point of aluminum in Celsius is not too high compared to many other metals, it is quite difficult to reach 600 degrees at home using an ordinary gas or electric stove .
Decrease temperature
Before subjecting the metal to melting, it is possible to reduce its melting point using special methods, for example, using it in powder form. In this case, it will begin to melt a little faster.
But at the same time it becomes dangerous, since when interacting with atmospheric oxygen it can oxidize or ignite.
And as a result of oxidation , as we remember from the school chemistry course, aluminum oxide is formed; and the temperature at which this substance begins to melt already exceeds two thousand degrees.
In general, it is not possible to avoid the formation of oxide if you melt aluminum, but it is quite possible to reduce the amount of excess substance. When melting aluminum, it is necessary to prevent water from entering the substance. After all, if this happens, there will be an explosion.
Before starting the process, you need to make sure that the raw materials are completely dry. Most often, aluminum wire is used as the starting material. First you need to use scissors to divide it into many small pieces. And in order to reduce the area of contact with the oxygen contained in the atmosphere, these pieces are pressed with pliers.
There is not always a need to create a high quality aluminum product, so it is not always necessary to use powder or finely chopped and tightly compressed wire.
You can take any item that has already been used, for example, a jar in which canned food was stored. But before melting, you need to deprive it of the bottom seam or cut the profile. The resulting raw materials can be painted or stained. No need to worry about it.
Anything that is superfluous on the surface quickly comes off in the form of waste.
Melting process at home
Melting is a rather dangerous process . You must first take care of the means of protection against various toxic substances that will be formed, and also prepare the casting mold.
Means of protection
- You cannot do without special gloves even if you only need to melt aluminum once. This is perhaps the main means of protection, since the molten mass can most likely get on your hands, and then a burn will inevitably appear on the skin, since the temperature of the liquid metal exceeds 600 degrees.
- The next part of the body that also needs to be protected from hot aluminum is the eyes. If you swim frequently, you cannot do without a special protective mask, or at least glasses. But it is best to work in a suit that is resistant to high temperatures of several hundred degrees.
- If it is necessary to obtain pure aluminum, a refining flux will be required. And then you need to work in a chemical respirator.
Source: https://vi-pole.ru/temperatura-plavlenija-djurali-aljuminija.html
At what temperature does aluminum melt?
The melting point of aluminum characterizes the gradient of transition to the liquid state and determines the physical parameters of the chemical element. The properties of the metal make it possible to use it in various branches of industrial production, and the ability to form stable compounds significantly expands the scope of its use.
The ability to change from solid to liquid determines the physical properties of a metal.
Characteristics of physical and technical parameters of aluminum
- Aluminum is one of the most common chemical elements and is characterized by light weight and softness. The basic physical parameters of the metal, the ability to form compounds resistant to environmental influences, allow it to be used in various branches of industrial production.
- Metal is an attractive material for working at home. The specific heat of fusion of aluminum is 390 kJ/kg, and for foundry purposes it is not difficult to melt it at home.
- Melting of metal can be carried out by surface and internal heating. The method of external thermal influence does not require special equipment and is used in artisanal conditions.
- Aluminum, the melting point of which depends on the purity of the compound and pressure, requires heating to an average of 660 °C or 993.5 °K to transform into a liquid state.
- There are different opinions regarding the melting temperature of metal at home, but they can only be verified in practice.
Properties of metal alloys
The temperature gradient indicator fluctuates for metal compounds with other chemical elements that determine their properties. For cast alloys containing magnesium and silicon, it is 500 °C.
The specific heat of fusion determines the physical property of a chemical element. For alloys, this indicator characterizes the process of transition from one state of aggregation to another in a certain temperature range.
The temperature at which the transition to the liquid state begins is called the solidus (solid) point, and the end point is called the liquidus (liquid) point. Accordingly, the beginning of crystallization will be determined by the liquidus point, and the end - by the solidus. In the temperature range, the compound is in a transition state from liquid to solid phase.
In some compounds of aluminum with other chemical elements, there is no interval between the temperature indicators of the transition from solid to melt. These alloys are called eutectic .
For example, a compound of aluminum with 12.5% silicon, like pure metal, has a melting point, not a range. This alloy is a casting alloy and is characterized by a constant temperature of 577 °C.
As the amount of silicon in the alloy increases, the liquidus gradient decreases from the maximum characteristic of pure metal. Among alloying additives, the temperature gradient reduces the use of magnesium (450 °C). For a connection with copper it is 548 °C, and with manganese it is only 658 °C.
Aluminum forms various alloys with minerals.
Most compounds consist of several components, which affects the rate of solidification and melting of the material. The concepts of temperature gradients solidus and liquidus are defined for the infinite duration of processes of equilibrium transitions into the liquid and solid states.
In practice, corrections to the heating and cooling rates of the compositions are taken into account.
Application of metal in industrial production
Under natural conditions, aluminum tends to form a thin oxide film, which prevents reactions with water and nitric acid (without heating). When the film is destroyed as a result of contact with alkalis, the chemical element acts as a reducing agent.
In order to prevent the formation of an oxide film, other metals (gallium, tin, indium) are added to the alloy. The metal is practically not subject to corrosion processes. It is a popular material in various industries.
Aluminum and its alloys are in great demand in various spheres of human life.
- Aluminum is considered a popular material for making tableware and the main raw material for the aviation and space industries. The excellent electrical conductivity of the metal allows it to be used for sputtering conductors in microelectronics.
- The property of aluminum and its alloys to become brittle at low temperatures allows it to be used in cryogenic technology. Reflectivity and low cost, ease of vacuum deposition make aluminum an indispensable material for the manufacture of mirrors.
- The application of metal to the surface of parts of turbines and oil platforms makes steel alloys resistant to corrosion. Metal sulfide is used to produce hydrogen sulfide, and pure aluminum is used as a reducing agent for rare alloys from oxides.
- The chemical element is used as a component of compounds, for example, in aluminum bronzes and magnesium alloys. Along with other materials, it is used for the manufacture of spirals in electric heating devices. Metal compounds are widely used in glass making.
- Currently, pure aluminum is rarely used as a material for jewelry, but its alloy with gold, which has a special shine and sparkle, is gaining popularity. In Japan, metal is used instead of silver to make jewelry.
- Aluminum is registered as an additive in the food industry. Aluminum beer cans have been a popular beverage packaging since the 1960s. The technological line provides for the production of containers of 0.33 and 0.5 liters. The packaging has the same diameter and differs only in height.
- The main advantage of packaging over glass is the possibility of recycling the material.
- Cans for beer (carbonated drinks) can withstand pressure up to 6 atmospheres, have a dome-shaped, thick bottom and thin walls. Features of the manufacturing technology by drawing ensure the structural strength and reliable performance properties of the container.
Source: https://steelfactoryrus.com/pri-kakoy-temperature-plavitsya-alyuminiy/
How to melt aluminum
Many people came up with this idea, but few did it. Let's look at how to properly melt aluminum at home.
Before starting work
First you need to decide on the size of the product and the scope of work:
- For smaller ones, a gas stove is suitable.
- For medium-sized ones - a homemade small oven made of refractory bricks
- For larger ones - a muffle furnace.
With any choice, you need to close the container with molten aluminum as much as possible from drafts and seal the walls as much as possible to reduce heat loss. Aluminum gives off heat quickly, so it is difficult to heat it under simple conditions. Let's look at how to achieve this.
What technologies exist for melting metal?
When using a gas stove, you need to remove the existing flat nozzle and install a special device on top of the grate - a cylinder, which can be made from any iron can of a suitable size. A 3-4 cm hole is made at the bottom of the cylinder, and 3 screws are tightened - they are needed so that the mold with aluminum inside the cylinder will stand on them.
A torch will come out of the camphor and enter the cylinder and heat the mold with the metal. The cylinder is needed to save heat and maximize the concentration of the flame around the mold. It is buried on top with a plate so that the heat does not escape, but a small gap is left for traction.
The same principle is used for stoves; large containers can be placed here due to minimal heat loss and large space inside the stove. A small grill is made, on which the molds are placed, after which the oven is closed as much as possible on all sides, leaving only small holes at the bottom and top for drafting.
A muffle furnace is an ideal home option for frequent work
A muffle furnace is similar to a simple “potbelly stove” only with thick walls. It can be either wood- or electric-powered, depending on your convenience. In the second case, the wire is stretched in a spiral from the inside of the bricks, closer to the mold.
Inside in the middle there is a crucible - a special container for melting metal. In this design, losses are minimized - the free space is occupied by the crucible, with a small gap of 5-10 cm remaining between it and the walls.
Due to the large thickness - 20-30 cm, the walls can be filled with various heat insulators to retain heat. It can be moved or made stationary, and therefore a heat insulator is selected. There is brick inside, iron outside, and how to fill the rest of the space is left to the discretion of each individual.
Metal smelting
When melting, it is important to use clean dishes (made of iron or non-ferrous metal). If you are melting it for the first time, it makes sense for further preparation. You need to clean the container, remove rust and debris, dust, rinse thoroughly, let it dry, and only then can it be used.
During cooking, remove floating slag - paint residues or dirt; they will significantly reduce the quality of the metal. After the metal has melted well, it needs to cool a little so that there is less splashing and it is more convenient to pour into molds. The latter should not be damp, so that evaporating moisture does not create bubbles in the product.
Here are two “sources of technology” - the videos themselves + comments on them.
There is more on the web, but this is exactly what I liked most - there is all the necessary information, and nothing superfluous.
Aluminum casting - 1
Aluminum casting - 2
I didn’t shoot my own video - since these two show everything perfectly - two typical technologies.
The temperature is maintained with a gasoline-powered blowtorch (92).
I've heard that some people add acetone, but I haven't done that. When the stove warms up, it begins to heat the pan from all sides. Of course, the blowtorch side heats up the most, and at first the opposite side of the pan cools down quickly.
But as the metal melts, it begins to heat itself + the stove does not allow it to cool (the thermal resistance of the thick walls of the stove is high, and the heat does not have time to escape). For uniform heating and, most importantly, to achieve a high temperature and reduce viscosity (increase in fluidity along with an increase in temperature), it was necessary to heat for 4 hours.
I work outdoors—it’s dangerous indoors. For more uniform heating and, most importantly, to speed up the process, I plan to make two additional holes in the stove and install two additional blowtorches. At first I thought about placing just one more opposite the first one, but then I decided that if I’m going to do it, then three at once – at 120 degrees.
Tip 1: How to mine aluminum
Then the heating will be completely uniform and very fast - I expect to melt the same amount of metal not in four hours, but in 4050 minutes - because not only will it heat up three times more intensely, but it will not cool down on the reverse side as before - so with By increasing the number of burners by 3 times, the melting speed will increase by a factor of five (I think so).
By the way, the very first melting was unsuccessful - in 3.5 hours I still did not melt the metal - it turned out that I started the burner too weakly. Moreover, the pan failed - it burned, and even what melted - everything flowed into the stove. So the first time it didn’t even get to the point of filling. The second time I immediately turned it on at full power, and took the correct pan - without a thick bottom. And everything worked out.
On August 12, I melted it again - I haven’t made additional burners yet, but I lined the pan inside the stove with coal for the barbecue - the process went much faster and more evenly, the melting took 3 hours instead of 4.
Making a stove - materials for making
Ready stove
grind the foam ball (we make a souvenir in the form of an aluminum ball with a profile cut)
Using sandpaper, sand the ball until smooth.
Transfer the drawing to the workpiece,
mill the profile groove and add a cylindrical sprue for pouring,
and pour liquid “Rotband” over everything to obtain a solid flask after hardening
just before pouring
immediately after filling
Casting freed from mold
Recently it was necessary to make a gear for a lawn mower to replace a plastic one, the protrusions for engagement with the pin had been ground off - the photo shows the places where there used to be plastic
fill three molds
here is the best casting - it is clear that the protrusions have been molded to replace the worn ones; minor modifications to the surface of the protrusions and gear teeth are required. But I don't like it and I will try again.
Read more (2015 update):
Making high-quality aluminum gear for a lawn mower
Updated November 20, 2015
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As is known, the melting point of aluminum is over 660°C. Using home heating appliances such as an iron, oven or gas stove, it is unlikely to achieve such a temperature. Therefore, smelting aluminum at home becomes possible with the appropriate equipment and, of course, the raw material for smelting - aluminum.
For melting aluminum, a homemade crucible muffle furnace is usually used. The peculiarity of this furnace is the top loading into the working chamber of the so-called crucible - a special ladle for melting aluminum, into which the raw materials are placed. The compact dimensions of the muffle furnace with vertical loading make it easy to store and use it at home on the balcony, in the garage or in the country house.
Now let's talk directly about the process of melting aluminum at home.
As already mentioned, to melt aluminum in a muffle furnace you need a crucible. It is usually made of a fire-resistant material or a metal with a much higher melting point than aluminum.
Corundum, graphite, porcelain, quartz, cast iron or steel are used to make crucibles. I managed to make a crucible from steel myself. You can buy a crucible from other materials ready-made, but making a homemade crucible from steel turned out to be much easier and more practical, especially if you have a welding machine and basic welding skills and operating a grinder.
The crucible size should be selected based on the amount of aluminum you want to melt. Heat must be transferred evenly from the hot crucible to the raw material. In turn, the crucible should also be heated evenly. For a muffle furnace of my design, I plan to make several crucibles of different volumes to work with one or two heating elements at the same time.
The aluminum is packed into the crucible as tightly as possible. To do this, it is advisable to grind the raw materials and slightly compress them. I used regular aluminum wire for melting, so I just cut it with wire cutters and pressed it tightly with pliers.
When melting, aluminum significantly decreases in volume compared to the original material (after all, in principle, we then melt it), so in the process of melting aluminum at home, we will need to periodically add raw materials to the crucible.
It should be noted that this can be extremely dangerous! The whole point is that moisture can linger somewhere in the raw materials we add, and when water gets into the molten aluminum, a sharp splash occurs, and the metal can splash out of the muffle furnace, damaging you with serious burns. And there will be absolutely disastrous consequences if molten metal gets into your eyes. Therefore, always monitor your safety - work exclusively in protective glasses or a mask, and even better - in a special fire-resistant metallurgist suit.
During the process of melting aluminum at home, an oxide film will form on the surface of the molten metal and any slag will float to the surface.
Need advice, aluminum smelting, casting
The amount of slag depends on the quality of the raw materials used to melt aluminum. Somewhere it was tinted, somewhere it was stained - all this will leave the metal in the form of slag. Immediately before casting molten aluminum into molds, it is recommended to remove the slag using a special device.
Also, after the aluminum has melted and formed a uniform shiny drop, as the liquid terminator did in the movie “Terminator 2,” it is recommended to keep the crucible in the oven a little longer to give the molten aluminum greater fluidity. This will greatly simplify further casting.
What's next? Obviously, you need to pour molten aluminum into a specially prepared casting mold. I wrote a separate article about this, which is called “Making molds for aluminum casting.”
Source: https://stroyvolga.ru/%D0%BA%D0%B0%D0%BA-%D1%80%D0%B0%D1%81%D0%BF%D0%BB%D0%B0%D0% B2%D0%B8%D1%82%D1%8C-%D0%B0%D0%BB%D1%8E%D0%BC%D0%B8%D0%BD%D0%B8%D0%B9/
At what temperature can iron be melted?
The table shows the melting point of metals tmelt , their boiling point tk at atmospheric pressure, the density of metals ρ at 25°C and thermal conductivity λ at 27°C.
The melting point of metals, as well as their density and thermal conductivity are given in the table for the following metals: actinium Ac, silver Ag, aluminum Al, gold Au, barium Ba, beryllium Be, bismuth Bi, calcium Ca, cadmium Cd, cobalt Co, chromium Cr, cesium Cs, copper Cu, iron Fe, gallium Ga, hafnium Hf, mercury Hg, indium In, iridium Ir, potassium K, lithium Li, magnesium Mg, manganese Mn, molybdenum Mo, sodium Na, niobium Nb, nickel Ni, neptunium Np , osmium Os, protactinium Pa, lead Pb, palladium Pd, polonium Po, platinum Pt, plutonium Pu, radium Ra, rubidium Pb, rhenium Re, rhodium Rh, ruthenium Ru, antimony Sb, tin Sn, strontium Sr, tantalum Ta, technetium Tc, thorium Th, titanium Ti, thallium Tl, uranium U, vanadium V, tungsten W, zinc Zn, zirconium Zr.
According to the table, it can be seen that the melting point of metals varies over a wide range (from -38.83°C for mercury to 3422°C for tungsten). Metals such as lithium (18.05°C), cesium (28.44°C), rubidium (39.3°C) and other alkali metals have a low positive melting point.
The most refractory metals are the following: hafnium, iridium, molybdenum, niobium, osmium, rhenium, ruthenium, tantalum, technetium, tungsten. The melting point of these metals is above 2000°C.
Here are examples of the melting point of metals widely used in industry and everyday life:
- melting point of aluminum 660.32 °C;
- copper melting point 1084.62 °C;
- melting point of lead 327.46 °C;
- melting point of gold 1064.18 °C;
- melting point of tin 231.93 °C;
- the melting point of silver is 961.78 °C;
- The melting point of mercury is -38.83°C.
Rhenium Re has the maximum boiling point of the metals presented in the table - it is 5596°C. Also, metals belonging to the group with a high melting point have high boiling points.
The density of the metals in the table ranges from 0.534 to 22.59 g/cm 3 , that is, the lightest metal is lithium, and the heaviest metal is osmium. It should be noted that osmium has a density greater than that of uranium and even plutonium at room temperature.
The thermal conductivity of metals in the table varies from 6.3 to 427 W/(m deg), thus the worst conductor of heat is a metal such as neptunium, and the best heat-conducting metal is silver.
Melting point of steel
A table of melting temperature values for common grades of steel is presented. Steels for castings, structural, heat-resistant, carbon and other classes of steels are considered.
The melting point of steel ranges from 1350 to 1535°C. The steels in the table are arranged in order of increasing melting point.
Melting point of steel - table- Volkov A.I., Zharsky I.M. Large chemical reference book. - M: Soviet School, 2005. - 608 p.
- Kazantsev E.I. Industrial furnaces. Reference manual for calculations and design.
- Physical quantities. Directory. A. P. Babichev, N. A. Babushkina, A. M. Bratkovsky and others; Ed. I. S. Grigorieva, E. Z. Meilikhova. - M.: Energoatomizdat, 1991. - 1232 p.
Source: https://crast.ru/instrumenty/pri-kakoj-temperature-mozhno-rasplavit-zhelezo
How can you melt aluminum at home?
Aluminum is a very common metal in both industry and households. It is not uncommon that when a part breaks, there is a need to smelt a replacement.
Melting aluminum at home is attractive because it is possible at a relatively low temperature.
To carry out the operation yourself, you need to know the characteristics of the metal when exposed to temperature and its physicochemical properties.
What is the melting point of aluminum?
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Question for experts: How to melt aluminum at home?
Best regards, Igor Sovetov
Best answers
Look here, maybe s will help. m/watch?v=cIlonSuReH0
G҈r҈o҈t҈e҈s҈q҈u҈e hul͝a͝b͝a͝lloo:
At what temperature does aluminum melt?
That's right, at a temperature of 660 degrees. An ordinary gas stove won’t give us this, and we shouldn’t do such things at home - it’s better to take the work outside. Let's look at how you can prepare solder by melting aluminum at home. Let us remind you once again that if you are not familiar with a soldering iron, then we would not recommend starting all this.
So, the price of aluminum ingots ranges from 55 to 150 rubles. per kg depending on the brand of alloy. If we are not aiming for a particularly high quality of work, then any will do. In principle, you can use scraps of the old profile.
To successfully complete the operation, we will need a portable gas torch or blowtorch. Depending on the model, they give a temperature of 1000 - 1300 degrees. This is quite enough.
What are we going to melt in?
For this we need a refractory container, for example, made of stainless steel. You can use a scoop bowl if nothing else is available. We will also need a calcined steel plate or another container into which we will pour molten aluminum.
We make a small “well” out of bricks, so that our container can be placed on top (by the way, it can be placed on skewers, they are also quite refractory). Before installing the container, we light a fire in the “well”. It will help keep the container warm when we stop using the burner. In addition, the fire will help warm up the aluminum from below.
When a certain amount of hot coals is formed, we place our container with aluminum and heat it for about 15 minutes. Here you can leave the second container or plate to warm up. After this, turn on the gas burner to maximum and heat the aluminum from above. The metal will begin to melt in just a few seconds, however , our goal has not yet been achieved - we need uniform heating.
To do this, the container must be shaken periodically. This should be done extremely carefully, using pliers and thick gloves (for welders this is the best). In principle, the molten composition can be stirred with steel wire (just as carefully). Please note that when using recycled materials (remnants of the profile), paint may evaporate, which is not recommended to breathe.
When melting, aluminum oxide is formed, which, in turn, forms scale. After the formation of homogeneous (corrected for scale) liquid aluminum, the container is carefully taken with pliers. The contents are poured onto a hardened steel surface.
It should be poured in such a way that only the metal pours out, and the scale remains in the original container (in principle, this is not difficult - the main thing is not to tilt it too much).
That's it, your molten aluminum is ready for further work.
ancient people melted iron, but you can’t melt some kind of aluminum..
You can also melt with the power of thought
Take an aluminum ladle, pour water into it, boil it, throw something in to cook, go about your business while it cooks, forget about all this, remember in an hour and a half, and then you know what to do.
answer
This video will help you figure it out
Answers from experts
About 600 degrees Celsius, it melts easily in a “dacha” fire.
To be more precise: 660 °C
560 degrees (melting)
At 600 degrees aluminum is cast (this is foundry temperature)
The metal is silver-white, light, density - 2.7 g/cm³, melting point for technical aluminum - 658 °C, for high-purity aluminum - 660 °C
Damn, I like some of the answers: I did a search on the Internet for “Aluminium melting”, found something similar, and put it in the “answer”. And a lot, and scientifically clever: -)))))))
In general, yes, Sergey! Your problem is solved. Let's start with the fact that you should develop a model for turning so that metal removal after casting is minimal. This is not for the sake of saving cheap aluminum, but for the sake of reducing labor intensity during turning.
Further.. . Considering the given load, we can say that the load is very light. I was somewhat confused that you are talking about the load “in different directions”, it seems like it’s cyclic. This is dangerous from the point of view of metal fatigue.
But still, 3.5 kg even for aluminum is not a problem. Therefore, the simplest type of pouring is quite suitable for you: chilled or in the ground. The chill mold can be machined according to a cast iron model. It will turn out great, but it will be labor-intensive.
For casting into the ground, you can use cement as a truss mixture: cheap and cheerful.
Let's return to the model: in order to minimize the number of casting defects, you MUST provide a feeder from which the metal will flow into the mold while crystallization is taking place in the mold.
Thus, most of the macrodefects associated with shrinkage will disappear from the part. If the shape is complex, then feeders must also be installed above the thermal units (usually narrow channels). Unfortunately, I won’t be able to explain the feeder placement system with my fingers.
I hope that your form is not complicated, and you will get by with only one - a sprue.
Often it is not pure aluminum that is used for casting, but silumin. Silumin contains silicon, and silicon promotes better filling of narrow channels. This is called "fluidity." But it can also be cast from aluminum. When melting, apply a flux of a mixture of table salt and carnalite to the mirror.
If possible, measure the temperature of the melt: you don’t need more than 750, your task is to quickly melt and drain. It is not advisable to exceed 700-720 degrees when pouring. It is better to do cooling slowly, for which you preheat the chill mold. If you pour it into the ground, then the thermal conductivity of the cement itself will do its job.
Of course, slow cooling leads to the growth of primary crystals (and this is bad), but there is a chance to minimize casting defects (inclusions, porosity, etc.).
It would be nice to homogenize the casting. To do this, after it has cooled, it must be heated to 550-600 degrees and kept for 10-20 hours. This will dissolve excess phases and relieve casting stress.
Just don’t forget about safety precautions: even though aluminum is fusible, even 660 degrees at which it melts will not give you pleasure if a splash occurs and gets on your skin. To avoid splashing, remember: THE FORM MUST BE PERFECTLY DRY!!!
Perhaps, just take a glass the size of the blank (diameter). Suitable raw materials include aluminum cans and electrical aluminum. The quality of the metal will be below average, but it will be suitable for file handles.
Melting of aluminum alloys is made difficult by their strong oxidation and saturation with gases when heated above 800°. There are several melting methods that ensure high quality casting: under a layer of flux, gas refining, salt refining, freezing and modification.
Melting under a layer of flux takes place in the following sequence. The charge materials are tightly placed in a crucible or furnace and covered with fluxes on top. Melt the metal in parts: first, about 1/3 of the charge, | then the rest of the charge material is heated to 100-120° to remove moisture from the surface and immersed | into the molten metal under a layer of fluxes.
Melting during gas refining is carried out as follows: first, 1/3 of the charge is melted, the alloy (Cu + Al; Al + Si) and the rest of the charge material are added. Then the alloy is stirred, heated to 660-680° and refined by blowing chlorine through it for 5-15 minutes. Such refining is classified as active, since chlorine in this case enters into a chemical interaction with aluminum and other elements:
The resulting gaseous products A1C1 3, HC1 and C1 2 are removed from the metal, taking with them A1 2 O 3, SiCb and gases.
After gas refining, the metal acquires high mechanical properties. In addition to chlorine, nitrogen can be used for gas refining.
Refining with salts during smelting is used in cases where gas refining with chlorine cannot be carried out. The charge materials are melted, heated to a temperature of 690-720° and refined with ZnCb, TiCb, BC 1 3 salts. Salts used for refining must be dehydrated and stored in hermetically sealed containers. In the absence of these conditions, salts will serve as a source of gas saturation of the alloy. Refining additives introduced into the alloy interact with aluminum according to the reaction:
Zinc or other elements (Ti, B) included in the refining salts remain in the alloy as impurities. During refining, the alloy is stirred, and after refining, it is allowed to age, since AlC1 3 is very slowly released from the metal. Pouring metal into molds without holding leads to the formation of gas porosity in the castings.
The use of freezing during melting is based on the fact that at the moment of solidification of non-ferrous metals, gases are released from them, and a minimum amount of gases remains in the solidified metal.
When the metal, which is a compact mass well covered with fluxes, is re-melted, some more gases will be additionally removed. After this, the alloy is heated to a given temperature and poured into molds.
This method is widely used in cases where the charge materials contain a large amount of recycled metal.
Modification of aluminum-silicon alloys during melting makes it possible to obtain a more uniform fine-grained structure of the metal. Before modification, the alloy is heated to 800-820° and covered from the surface with a mixture of dehydrated salts: 67% NaF + +33% NaCl (in an amount up to 2% by weight of the metal).
The alloy is kept under a layer of flux for 12-14 minutes. The modified alloy retains its properties for a short time (10-12 minutes), so it must be quickly poured into molds. In this regard, modification is not recommended in large furnaces.
The alloy obtained from a large furnace is poured into special crucibles, modified in them and poured into molds.
Complex smelting methods combine several methods discussed above.
* Castings from aluminum alloys. * Alloys, aluminum with copper. * Complex aluminum alloys. * Furnaces for melting aluminum alloys. * Methods for melting aluminum. * Gating systems for aluminum alloys. * Castings from magnesium alloys. * Furnaces for melting magnesium alloys. * Gating systems for magnesium alloys.
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It seems to me that the choice of material and manufacturing method is wrong. You can almost always bend the same thing out of steel and weld the stiffeners, the result will be lighter and stronger. But if you are casting, then you need to choose a cast alloy, not a wrought one. Silumin is suitable for any type of AL. And duralumin flows poorly. That is, debris from the engine (from the cylinder block) will do, but scraps of aluminum sheet will not.
There is no need for any special modes when casting - heat the lumine until completely melted, pour it into a tall iron pan or glass and let it cool. It will come out of the pan easily - it will not burn or cook. When turning, clamp it into the chuck with the top of the ingot (there will be a shell or loose space inside).
Source: https://dom-voprosov.ru/prochee/kakaya-temperatura-plavleniya-alyuminiya
Composition and structure of aluminum
Aluminum is the most common metal in the earth's crust. It is classified as a light metal. It has low density and mass. In addition, it has a fairly low melting point. At the same time, it has high ductility and shows good thermal and electrical conductivity characteristics.
Aluminum crystal latticeAluminum structure
The tensile strength of pure aluminum is only 90 MPa. But, if you add some substances to the melt, for example, copper and a number of others, then the tensile strength increases sharply to 700 MPa. The same result can be achieved using heat treatment.
Aluminum, which has extremely high purity - 99.99%, is produced for use in laboratory purposes. For industrial applications, commercially pure aluminum is used. When producing aluminum alloys, additives such as iron and silicon are used. They do not dissolve in the aluminum melt, and the additive reduces the ductility of the base material, but at the same time increases its strength.
Appearance of a simple substance
The structure of this metal consists of simple cells consisting of four atoms. This structure is called face-centric.
Calculations show that the density of pure metal is 2.7 kg per cubic meter.
Properties and characteristics
Aluminum is a metal with a silvery-white surface. As already noted, its density is 2.7 kg/m3. The temperature is 660°C.
Its electrical conductivity is equal to 65% of copper and its alloys. Aluminum and most of its alloys are resistant to corrosion. This is due to the fact that an oxide film forms on its surface, which protects the base material from exposure to atmospheric air.
In the untreated state, its strength is 60 MPa, but after adding certain additives it increases to 700 MPa. The hardness in this state reaches 250 HB.
Aluminum can be easily processed under pressure. To remove work hardening and restore ductility after processing, aluminum parts are annealed, and the temperature should be within 350°C.
Melting point of aluminum
The production of aluminum melt, like many other materials, occurs after thermal energy has been supplied to the original metal. It can be supplied either directly into it or from outside.
The melting point of aluminum directly depends on the level of its purity:
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- Ultra-pure aluminum melts at a temperature of 660.3°C.
- With an aluminum content of 99.5%, the melting point is 657°C.
- With a content of this metal of 99%, the melt can be obtained at 643°C.
Aluminum meltAluminum production process
An aluminum alloy can contain various substances, including alloying ones. Their presence leads to a decrease in the melting point. For example, if there is a large amount of silicon, the temperature can drop to 500°C. In fact, the concept of melting point applies to pure metals. Alloys do not have any constant melting point. This process occurs within a certain heating range.
In materials science there is a concept - solidus and liquidus temperatures.
The first temperature indicates the point at which the melting of aluminum begins, and the second shows at what temperature the alloy will finally melt. In the interval between them, the alloy will be in a mushy state.
Selecting a mold for casting
When choosing a mold for casting aluminum, a home craftsman must understand for what purpose he is processing aluminum. If the future casting is intended for use as solder, then there is no need to use any special forms. To do this, you can use a metal sheet on which to cool the molten metal.
But if there is a need to obtain even a simple part, then the master must decide on the type of mold for casting.
The mold can be made from plaster. To do this, gypsum in a liquid state is poured into an oil-treated mold. After it begins to harden, a casting model is installed into it. In order for molten metal to be poured into the mold, a sprue must be formed.
To do this, a cylindrical part is placed in the mold. Forms can be detachable or not. The process of making a split mold is complicated by the fact that the model will be in two halves. After hardening, they are separated, the model is removed and connected again. The form is ready to use.
Aluminum casting die
To obtain high-quality castings, it is advisable to use metal molds (moulds), but it is advisable to produce them only in factory conditions.
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Source: http://ooo-asteko.ru/pri-kakoy-temperature-plavitsya-alyuminiy/
Melting aluminum at home at high temperatures - Ice advice
Aluminum is a metal that is widely used in industry and everyday life. ?>
It is used to produce not only aircraft and ship parts, but also dishes and other utensils. Therefore, there is often a need to independently manufacture aluminum parts that have failed.
The ability of aluminum to melt at relatively low temperatures makes it possible to produce cast products from it in artisanal conditions. In order to independently produce cast aluminum products, you need to know the behavior of this metal at high temperatures and its physical and chemical properties.
Characteristics of aluminum
The melting point of aluminum depends on the purity of the metal and is approximately 660 °C. Its boiling point is 2500 °C.
Aluminum is distinguished by its lightness and ductility, so it bends well and can be processed by stamping.
This metal is an excellent conductor of heat and actively enters into a chemical reaction at high temperatures with atmospheric oxygen, forming an oxide film on the surface. It protects aluminum from further oxidation, but when scrap melts, it significantly affects the composition of the alloy. During the metal smelting process, the structure of aluminum changes.
Technologies for home aluminum casting and necessary equipment
The principle of casting aluminum at home should be based on the technology for its production in production, adjusted for conditions that can be used at home.
Aluminum products are produced by casting in several ways. In domestic conditions, the most common and convenient method is the technology of casting molten aluminum into specially made molds.
Therefore, to carry out the process, two things must be ensured:
- build a furnace for melting aluminum scrap;
- create the desired shape to produce a cast alloy or a separate part.
The casting process must include several stages:
- Preparation of aluminum scrap, including cleaning from dirt, impurities and various fillers, as well as grinding it to a small size.
- Carrying out the smelting process in the planned way. When the metal is completely melted, slag formations must be removed from its surface.
- Filling the prepared mold with liquid aluminum melt. After solidification, the ingot is freed from the molding mass.
Let's consider how to melt aluminum at home, what designs of furnaces for melting metal can be used, as well as options for making molds yourself.
In order to melt aluminum, you need to heat it to a temperature close to 660 °C. It is impossible to reach such a temperature on an open flame of a fire. Therefore, a closed space is needed, which a homemade stove can provide. It can be heated by burning coal and wood or using natural gas.
You can also use an electric muffle furnace if you have one on the farm.
With a self-made stove, forced ventilation must be provided to maintain the combustion process.
1. The simplest version of a homemade fireplace can be made from old pots.
Its design is as follows:
- As a frame, use a steel container, for example, an old pan, on the side of which you need to make a hole to supply air through a connected metal pipe.
- Air can be forced through the hose using a vacuum cleaner.
- Coal is placed inside the device.
- Then the coal is set on fire and air is supplied to keep the fire from going out.
- A container for melting aluminum is first placed inside an improvised furnace structure and lined with coal on its sides. When it burns, uniform heat distribution is ensured.
- To prevent heat from being lost to the surrounding air, the top of the “pan” stove should be loosely covered with a lid, leaving a small gap for the smoke to escape.
An ideal design would be a firebox with an oval arch made from a masonry mixture used for heat-resistant bricks. You can use a flower pot of the desired size as a frame to create an oval vault.
After the mixture dries, a good firebox is obtained that can withstand several heats.
2. The second version of the furnace involves using the flame of a household gas burner to heat aluminum.
It can only be used for piece products made of aluminum weighing no more than 150 grams. An imitation oven is created by using two containers inserted into each other with a small gap. These can be ordinary cans from canned food.
The outer jar should be larger. A hole with a diameter of about 4 cm is made in it to ensure the supply of flame to the inner can.
The flame jet should be directed towards the opening of the can. Only the inner container is heated directly, and the outer one serves as a shell that retains heat. The top of the structure must be covered with a simulated lid, leaving a gap for the removal of combustion products.
This design is disposable and can only be used for one melt, since the tin is thin and can quickly burn out.
Methods for creating a mold for casting aluminum
One of the main tasks of home aluminum smelting is preparing the mold into which the molten metal is poured. There are different options for pouring aluminum melt. The main ones are open and closed casting methods.
Open casting
The simplest is to pour the liquid metal into a handy form, such as a metal mug or can.
After the alloy has hardened, the blank is removed from the container. To facilitate this process, tapping is performed on the form that has not completely cooled down.
Closed form
If it is necessary to obtain a complex casting, a mold is first made for it that meets all the parameters of the part. To ensure strict compliance of the product with the specified parameters, it is made from composite molding parts.
Materials for casting molds
With the open pouring method, the simplest material that is always at hand is often used, this is silica. First, the earth is laid with layer-by-layer compaction. A casting model is placed between the layers, which, after careful compaction, leaves an imprint in the silica. This mold is carefully removed and aluminum is poured in its place.
Some craftsmen use river sand with the addition of liquid glass when preparing the base of the mold. A mixture of cement and brake fluid is also sometimes used.
Plaster molds
When making a model of a complex shape, gypsum is often used, which can mainly be used for a one-time casting process. When casting aluminum into a plaster mold, paraffin or foam plastic is used as models.
The wax model of the product is filled with plaster and, after drying it at high temperature, it is melted and drained through a special hole.
If the model is made from foam plastic, it is filled with gypsum mixture and left in it until the mold completely hardens. Hot aluminum melt is poured directly onto the foam. Due to the high temperature of the metal, the foam melts and evaporates, and its place is taken by an aluminum melt, taking the shape specified by the foam.
Typical mistakes and tips for proper casting
- When working with plaster, you should avoid common mistakes. Despite the fact that plaster molds are a convenient way to cast the desired configurations of parts, this material is very sensitive to moisture. During normal air drying, it remains part of the gypsum. This is detrimental to the quality of the aluminum casting, as it can cause the formation of small shells and bubbles. Therefore, plaster molds need to dry for several days.
- The metal must be hot enough before pouring to fill the entire mold before it begins to harden. Therefore, after reaching the melting temperature, taking into account the rapid cooling of aluminum, there is no need to delay pouring it into the mold.
- It is not recommended to immerse the resulting casting in cold water to speed up the hardening process. This can disrupt the internal structure of the metal and lead to cracks.
Source: https://LEDsovet.ru/plavka-aluminiia-v-domashnih-ysloviiah-pri-vysokoi-temperatyre/
