Abnormal Tensile Strength of Cast Mg-5Sm-4Gd Alloy
The room and high temperature tensile strengths of cast Mg-5Sm-4Gd alloy were studied by electronic tensile tests,and microstructure,rare earth phase and tensile fracture analysis.The results showed that the tensile strength of Mg-5Sm-4Gd alloy increased first and then decreased with increasing temperature,and had an abnormal temperature effect.The microstructure was mainly composed of α-Mg matrix and rare earth phases Mg41Sm5 and Mg5Gd,and the average grain size was about 200 μm.The tensile fracture mode was mainly brittle fracture at room and high temperature.The abnormal temperature effect of tensile strength should be related to grain size of the alloy,the lattice constant of α-Mg matrix and the thermal stability of rare earth phases.
Mg-5Sm-4Gd alloytensile strengthabnormal temperature effectrare earth phase