Al-Mn-Si

Al-Mn-Si is another core system to aluminum alloys. Mn is often added to suppress the formation of the detrimental τ5: α-Al8Fe2Si and τ6: β-Al9Fe2Si2, via forming the α-AlMnSi phase (named as AL15SI2M4, M=Cr, Fe, Mn, Mo). The α-AlMnSi phase originates in the Al-Mn-Si ternary system and extends towards the Al-Fe-Si system via the substitution of Fe for Mn. The substitution of Cr and Mo for Mn is also modeled in the TCS Al-based Alloy Database (TCAL).

Al-Mn-Si vertical section at 4 wt. % Si.

Figure 1: Al-Mn-Si vertical section at 4 wt. % Si (β-AlMnSi: τ8; α-AlMnSi: τ9 ) [2014Che].

Reference

[2014Che] H. Chen, Q. Chen, Y. Du, J. Bratberg, A. Engström, Update of Al-Fe-Si, Al-Mn-Si and Al-Fe-Mn-Si thermodynamic descriptions - TNMSC. Chinese J. Nonferrous Met. 24, 2041–2053 (2014).