This material specification applies to aluminum alloys for cast parts for automotive and other allied industries. Aluminum casting alloys are specified by chemical composition and thermal treatment. This standard governs only the chemical composition of parts made with aluminum alloys that represent common materials for identical product requirements across GM worldwide. Casting processes, thermal treatments, casting quality, microstructure and mechanical properties are discussed, but are not controlled by this standard.

Material Description. Most metallic elements readily alloy with aluminum, but only a few are used in commercial aluminum based alloys. Principle alloying elements include Si, Cu and Mg. Additional elements such as Mn, Na, Sr and Ti serve as supplementary alloying additions for improving material properties and casting characteristics. Other elements appear as impurities, which can affect alloy cost and product properties.

Symbols. Not applicable.

Typical Applications. Aluminum castings are widely used in automotive applications. Typical applications and alloy selection criteria for major subsystems are given in Appendix A.

Remarks. Appendix B contains a cross reference between GMW5 alloys, ISO 3522, and key European, Asian and American standards and is presented for reference only. GMW5 requirements may differ from those in other specifications. Cross referenced alloys are not interchangeable with their GMW5 counterpart.