Analysis of the Phase Composition of the Al–Cu–Mn–Ca System as the Base for Heat-Resistant Aluminum Alloys

The phase composition of the Al–Cu–Ca–Mn alloys containing (wt %) 6% Cu, 2% Mn, and to 4% Ca is analyzed. The Al–Cu–Ca–Mn phase diagram in the Al corner is proposed, according to which five four-phase regions with the participation of Al-based solid solution (Al) and various intermetallic compounds are possible to exist in the solid state. The Al–6% Cu–1% Ca–2% Mn composition is suggested as the base for developing new-generation heat-resistant (hot-strength) alloys. In the case of such contents of alloying elements, the combination of aluminum matrix containing Al₂₀Cu₂Mn₃ dispersoids and (Al) + Al₂₇Ca₃Cu₇ eutectic characterized by fine structure is possible.