Precipitation-hardening in cast AL–Si–Cu–Mg alloys

摘要: Age-hardenable aluminum–silicon alloys have attracted increasing attention in recent years, particularly as a result of the demand for lighter vehicles part overall goal to improve fuel efficiency and reduce vehicle emissions. Among these aluminum cast alloys, 319-type become object extensive investigation considering their practical importance transport industry. All experimental variables, such solidification condition, composition, heat treatment, are known an influence on precipitation behavior; precipitation-hardening, however, is most significant because presence excess alloying elements from supersaturated solid solution which form fine particles consequently act obstacles dislocation movement. The precipitation-hardening behavior Sr-modified alloy containing 0.4% Mg was investigated this study using transmission electron microscopy. Non-conventional aging cycles were applied so evaluate degree improvement strength potentially obtainable. results show that main strengthening phase θ-Al2Cu occurring plates; other phases observed minor constituents alloy, including binary β-Mg2Si, ternary S-CuAlMg2, quaternary Q-Al5Cu2Mg7Si7.