Adding an appropriate amount of alloying elements such as copper, magnesium, silicon, manganese, zinc, etc. to aluminum to form an aluminum alloy has excellent properties such as low density, high specific strength (the ratio of strength limit to density), and good thermal conductivity. If subjected to cold processing or heat treatment, its strength can be further improved. Aluminum alloys can be divided into two categories: deformed aluminum alloys and cast aluminum alloys.
(1) Deformed aluminum alloy: Deformed aluminum alloy has good plasticity and is suitable for pressure processing such as rolling and forging. According to their performance and application, they can be divided into rust proof aluminum alloy, hard aluminum alloy, and forged aluminum alloy. Among them, hard aluminum alloy is the most widely used. It is an alloy of aluminum, copper, and magnesium, with a strength of up to 420 MPa (N/mm2) and a hardness of around 100HBS after heat treatment. The disadvantage of hard aluminum alloy is its poor corrosion resistance. In mechanical manufacturing, some components that require lightweight and moderate strength are commonly made of hard aluminum alloy.
(2) Casting aluminum alloy: Many parts on knitting machines, winding machines, and warp knitting machines in textile machinery are made of cast aluminum alloy. Casting aluminum alloy is suitable for manufacturing castings with complex shapes or large volumes. It has excellent castability and good corrosion resistance, and can be strengthened by heat treatment. To improve its mechanical properties, it is necessary to perform a modification treatment before casting.