Aluminum is a light metal of white color withsilvery tinge, soft (it is possible to bend hands), it is well processed, at the same time strong enough. It is an excellent conductor of heat and electricity. In pure form, aluminum is almost not used, its application is practiced in the form of alloys with copper, carbon, tin, titanium, manganese and zinc. In terms of electrical and thermal conductivity, aluminum is second only to silver and copper. At the same time, impurities of vanadium, chromium and manganese reduce these indices.
Aluminum actively reacts with acids andalkalis, forming chlorides, sulfates, aluminates and other compounds. In air, the metal is instantly coated with an oxide film, which protects it from subsequent oxidation. The melting point of aluminum is within 660.1 degrees, the metal in the molten form has good fluidity. This metal is characterized by high plasticity, frost resistance, corrosion resistance when interacting with distilled and fresh water.
Experts note that corrosion resistancedepends on the purity of aluminum - the higher it is, the greater the durability. The cause of corrosion can be surface disturbances of the oxide film. It is proved that the melting temperature of aluminum rises as its purity increases. Having excellent casting qualities, the metal during crystallization gives a great shrinkage, this index is important in the manufacture of responsible casting from this metal.
The melting point of aluminum can fluctuate independing on the material used as an impurity. Leaders in the production of aluminum at present in the world are Russia, the United States, Canada, Australia. The range of use of aluminum is quite large, our ancestors aluminum in the form of compounds (alum) was used as an astringent in medicine, for tanning leather, to extend the shelf life of paints.
The sufficiently low melting point of aluminum made it possible to melt it in primitive conditions.
In nature, there is alumina (corundum), itIt is used as an abrasive material, and its varieties - sapphire and ruby - belong to the category of precious stones. Since in pure form aluminum is not suitable for technical applications, it is often used as a raw material for manufacturing various alloys. The spectrum of aluminum alloys is quite extensive, it is constantly replenished (with the use of different technologies).
Currently, such alloys are producedfood cans, cans, kitchen utensils and various household items. Important consumers of aluminum alloys are automobile, electrical, instrument-making, chemical, defense, metallurgical industries. At what temperature aluminum melts, it is taken into account in the manufacture of components for the defense, space and nuclear industries.
One of the most common color alloysis duralumin, it was developed in the last century by the German engineer A. Wilm. The melting point of duralumin was approximately 650 degrees. The essence of his invention lies in the fact that the aluminum-based alloy after heat treatment acquires great strength and hardness. This was immediately used by specialists and allowed to fly aeronautics. The new alloy has become one of the main structural materials in the aircraft industry.
Currently, the term duraluminimplies a large selection of aluminum alloys, characterized by high strength. Modern alloys except copper contain manganese, silicon, magnesium, etc., in strength they approached low-carbon steel. Today these alloys are widely used in the aviation industry, in the production of high-speed trains and in a number of other cases.</ p>