Effect of chemical compositions on tensile behaviors of high pressure die-casting alloys Al-10Si-yCu-xMn-zFe

Abstract

Effects of chemical compositions on the tensile properties, deformation behavior and fracture mechanism have been studied in a die-casting aluminum alloys Al-10Si-yCu-xMn-zFe. The test specimens were taken from the engine support brackets and tested at 20°C, 150°C and 300°C. Addition of Mn and Cu elements in the Al-10Si alloys can significantly increase the YS and UTS of the alloys. The as-cast Al-10Si-1.5Cu-0.8Mn-0.15Fe alloy exhibits the highest tensile properties (RT: YS of 190MPa and UTS of 308MPa, 150°C: YS of 176MPa and UTS of 249MPa, 300°C: YS of 94MPa and UTS of 111MPa). Increasing test temperature reduces the YS and UTS and improves the ductility of the alloys. Chemical compositions (such as Mn, Cu and Fe) do not significantly affect the work-hardening behavior of the alloys. Increasing test temperature significantly decreases the n and k values. Phase particles (both Si and (Fe/Mn)-rich) cracking and debonding determine the fracture mechanism of the alloys. Final failure of the alloys mainly depends on the global instability (HT, necking) and local instability (RT, shearing).