Influence of Added Fourth Elements on Precipitation in Heat-Resistant Al–Mg–Zn Ternary Alloys

In the present study, we investigated effects of Cu or Ni additions on precipitation intermetallic phases in heat-resistant aluminum alloy with a ternary composition Al–5Mg–3.5Zn (mol%). The quaternary alloys 1 mol%Cu mol%Ni content were solution-treated at 480°C and subsequently aged 300°C for different periods. Both have slight effect age-hardening these 300°C. added element partitioned into not only T-Al6Mg11Zn11 phase but η-Zn2Mg precipitated α-Al matrix. observed enrichment precipitates T indicated high stability Al–Mg–Zn–Cu system, which was from results thermodynamic calculations using existing database. enhanced formation fine Al3Ni located grain boundaries slightly influenced interior. These provided new insights to design novel Al Al–Mg–Zn–Cu–Ni system.