Al-Cu-Mg-Si

Aluminum alloys based in the quaternary system Al-Cu-Mg-Si are widely used, e.g. in the automotive and aerospace industry. The Al-Cu-Mg-Si family of aluminum alloys may exist either as a 6xxx or a 2xxx alloy. These alloys have distinctive properties in part due to the occurrence of the Q phase, which is stable as a quaternary compound.

This TCS Al-based Alloy Database (TCAL) vertical section example shows satisfactory agreements between experimental data and calculations on phase equilibria at 60 wt.% Al, 8 wt.% Si, involving Q, θ (Al2Cu), liquid, β(Mg2Si), (Si), S_PHASE, and T_PHASE.

Calculated vertical section at 60 wt.% Al, 8 wt.% Si with experimental data

Figure 1: Calculated vertical section at 60 wt.% Al, 8 wt.% Si with experimental data from [1949Pet].

Reference

[1949Pet] D. A. Petrov, N. D. Nagorskaya, Constitution diagram of the aluminum-copper-magnesium-silicon system. Zhurnal Obs. Khimii 19, 1994–2037 (1949).