A TEM study of precipitates in an Al-Mn-Si alloy

Abstract

Two types of intermetallic precipitates were found in aluminum alloy 3003 creep tested at 300°C. These precipitates are an Al₁₂(MnFeCu)₃Si₂ precipitate having a simple cubic structure with a = 1.2556 nm and an Al₆Mn-type precipitate with an orthorhombic structure with a = 0.6506 nm, b = 0.7501 nm, and c = 0.8800 nm. High resolution lattice imaging indicated the presence of a number of defect structures in the polycrystalline Al₁₂(MnFeCu)₃Si₂ precipitates.