Influence of Addition of Small Amount of Si on Hot-Tearing of Non-Thermally Treated High Pressure Al-Mg Based Die Casting Alloy for Automotive Body Parts

Abstract

  Al-Mg alloy is a strong candidate material for automotive body parts because it does not require heat treatment and has excellent ductility. However, the hot-tearing susceptibility of Al-Mg based alloy is higher than the conventional Al-Si based alloy. In this study, the influence of Si addition (0-0.30%) on the hot-tearing susceptibility in Al-4.5%Mg-1.0%Mn alloy added with 0.025%Sr, 0.08%Ti, and 0.016%B was systematically investigated. The I-beam test in which both ends of the test piece are constrained was used to evaluate the hot-tearing susceptibility. The results suggested that hot-tearing susceptibility reduced with increasing of Si addition when 0.025%Sr, 0.08%Ti, and 0.016%B was added.