General characteristics of pure aluminum

General characteristics of pure aluminum

1. Low density

The density of pure aluminum is close to 2700Kg/m3, which is about one-third of that of iron or copper.

2. Strengthenable

Although the strength of pure aluminum is not high, the tensile strength in the annealed state is about 80MPa, and its strength can be more than doubled by cold working. Higher strength can be obtained by adding alloy chemical elements such as magnesium, zinc, copper, manganese, silicon, lithium and further strengthening by heat treatment. At present, we can obtain aluminum alloys with a tensile strength greater than 700MPa, and its specific strength is comparable to that of high-quality alloy steel.

3. Easy to process

Aluminum can be cast by any method. Aluminum has good plasticity and fast processing speed. It can be rolled into thin plates and foils; drawn into pipes and filaments; extruded into profiles with various complex cross-sections; and can be turned, milled, bored, planed and other mechanical processes at the maximum speed that most machine tools can achieve.

4. Corrosion resistance

A dense and firm Al2O3 protective film is easily generated on the surface of aluminum and its alloys. This protective film will only be destroyed under the intense action of alkaline solution or halogen ions. Therefore, aluminum has good resistance to atmospheric corrosion (including industrial atmosphere and marine atmosphere) and water corrosion. It can resist corrosion from most acids and organic matter, and can resist corrosion from weak alkaline solutions by using corrosion inhibitors; protective measures can improve the corrosion resistance of aluminum alloys.

5. No low-temperature brittleness

Below zero degrees Celsius, the strength and plasticity of aluminum will not decrease with the decrease in temperature, but will increase instead.

6. Good electrical and thermal conductivity

The electrical and thermal conductivity of aluminum is second only to the thermal conductivity of silver, copper and gold copper. Under greenhouse conditions, the isovolumetric conductivity of electrical aluminum can reach 63% IACS; if calculated by unit mass conductivity, its conductivity is twice that of copper.

7. Strong reflectivity

The reflectivity of the polished surface of aluminum to white light is greater than 80%, and the higher the purity, the higher the reflectivity. In addition, aluminum also has good reflectivity for infrared, ultraviolet, electromagnetic waves, and thermal radiation.

8. Non-magnetic, no sparks when impacted

This property is very important for some special uses such as instrument materials, shielding materials for electrical equipment, and equipment for the production of flammable and explosive materials.

9. Sound absorption

It is beneficial for interior decoration and can also be made into shock-absorbing alloys.

10. Nuclear radiation resistance

For high-energy neutrons, aluminum has the same degree of neutron absorption cross-section as other metals; for neutrons in the low-energy range, the absorption interface is small, second only to beryllium, magnesium, zirconium and other metals. The reason why aluminum can resist nuclear radiation is that its induced radiation generated by irradiation decays very quickly.

11. Beautiful

Aluminum and its alloys have strong reflective ability and a silvery-white luster on the surface. After machining, they can obtain a very high finish and brightness. After anodizing and coloring, not only can a colorful and bright surface be obtained, but also its corrosion resistance can be further improved. Aluminum can also be electroplated and covered with ceramics, and is a good substrate for the production of coating materials. After painting, no cracks or peeling will occur, and even if there is local damage, no corrosion spots will be long-lasting.

12. Non-toxic

Pure aluminum and its alloys are non-toxic and do not react with food, so they are widely used in food packaging and kitchen utensils.

13. High recycling value

Pure aluminum and its alloys have high recycling value, low energy consumption in the recycling process, and almost no impact on the performance of the material, which meets environmental protection requirements.