Effect of Pre-stretching Process on Quenching Residual Stress of EW75 Magnesium Alloy

stress Abstract. This paper studies the effect of pre-stretching process on the residual stress and mechanical properties of EW75 magnesium alloy by OM and mechanical tests, etc. The results show that the bend deformation caused by the release of quench residual stress increases after machining into the pre-stretching sample. For the pre-stretching rate of 1.0%,1.5%,2.0% and 2.5%, the strain stress curves are similar and rebound phenomenon happens after unloading and varying degrees of twin deformation happens both in the surface and the core. When the deformation rate is 1%, the ultimate tensile strength of the material increases 20%, the yield strength increases 43%, while the fracture elongation reduced 30% subsequently. As the pre-stretching rate continues to increase, the yield strength, ultimate tensile strength and elongation are little changing.