Alloys of the 4th series are aluminum alloys with silicon as the main alloying element. Most of these alloys belong to nonheat treatable aluminum alloys. Only alloys containing Cu, Mg and Ni and those which absorb certain elements after welding heat treatment can be strengthened by heat treatment. Due to the silicon content, low melting point, good fluidity of the melt, easy to fill and not to make the final product brittle, this series of alloys are mainly used to the addition materials of aluminum alloy welding, such as brazing sheet, welding rod and welding wire, etc. In addition, some alloys of this series have good wear resistance high temperature resistance, and are also used to make pistons and heat-resistant parts. Alloys containing about 5% silicon are black-gray after anodic oxidation, so they are suitable for building materials and the manufacture of decorations. At present, the produced 4th series aluminum alloy brand: 4032.
