Aluminum casting alloys

Casting aluminum alloys are used to manufacture shaped parts. They have low density and high strength. The alloys have good fluidity, low shrinkage, low tendency to form hot cracks and porosity, very high mechanical properties, and corrosion resistance. Among casting alloys, the most interesting are aluminum-silicon alloys - silumins. To improve mechanical properties, silumins are additionally alloyed with magnesium, copper, and manganese. Iron is a harmful impurity in them. Alloys AK7 and AK9 are used to manufacture large loaded parts, such as compressor housings, crankcases and engine cylinder blocks. Silumins are strengthened by quenching and aging. Alloys of the Al-Cu system are used to cast small parts of simple shape, for example, fittings, brackets. Alloys of the Al-Mg system are intended for castings operating in a humid atmosphere, for example, in shipbuilding and aviation. Heat-resistant alloys include AM4Мг, from which pistons and cylinder heads are made, operating at a temperature of 275-300 °C, as well as alloys AЛ33, AM5.