This invention discloses an AlCuMnMgSiZr heat-resistant aluminum
alloy sheet containing Er, Sn, and Ag, and its preparation method. The composition of the sheet by weight percentage includes: Cu 4.0-5.6%, Mg 0.1-0.35%, Mn 0.2-0.4%, Zr 0.1-0.3%, Si 0.1-0.3%, Er 0.05-0.25%, Sn 0.05-0.20%, Ag 0.1-0.8%, with the balance being Al and unavoidable impurities. This invention utilizes multi-component composite microalloying of Er, Sn, Ag with Si, Mg, and Zr, combined with homogenization, hot rolling,
solution treatment, and aging, to leverage the multi-scale synergistic strengthening and stabilizing effects of the Al3(Er,Zr) composite phase, Ω phase, and θ' phase. This results in a
sheet material exhibiting high strength and excellent long-term
thermal stability across a wide temperature range, from ultra-low temperatures (-196℃) to high temperatures (300℃), while also improving
corrosion resistance. This
sheet material is particularly suitable for critical structural components in reusable rockets, such as cryogenic storage tanks and
rocket skin, which require resistance to severe thermal
cycling.