Microstructure and tensile properties of squeeze cast magnesium-aluminum-strontium alloys.

摘要

It has been demonstrated that die cast Mg-AI-Sr alloys have enhanced high temperature properties and are capable of replacing certain existing aluminum power train components. However, due to the inherent nature of die casting, i.e. high porosity content and other defects, automotive applications of Sr-containing magnesium die casting are very limited. Squeeze casting has a super ability to eliminate porosity and other casting defects. However, there is a general lack of understanding concerning the microstructure and tensile properties of squeeze-cast Mg-Al-Sr alloys.;This thesis describes the findings of experimental investigation in obtaining an in-depth understanding on the effect of pressure levels and strontium contents on tensile properties and microstructure of squeeze cast Mg-Al-Sr alloys. The results have shown that the ultimate tensile strength (UTS), yield strength (YS) and elongation (Ef) of squeeze cast Mg-Al-Sr alloys increase with increasing applied pressures but decrease as the strontium content increases.