Investigation Of Quasi-static Mechanical Properties Of Extruded Binary Mg-RE Alloys

Magnesium alloys usually show up low plasticity at room temperature, and it has great theoretical and realistic significance for the plastic processing of magnesium alloys to study their plasticity in order to improve their plasticity deformation ability. Binary magnesium alloy bars of Mg-Nd、My-Dy and Mg-Er with equiaxed grains were obtained by alloy smelting, hot extrusion and heat treatment in this paper. By comparing of avariety of Mg-RE alloys, the effects of rare-earth elements to the texture formation and microstructure of Mg-RE alloys during the hot extrusion and the static mechanical properties were studied. The results indicate that:(1) Recrystallization annealing was applied to as-cast Mg-Nd alloys after extrusion. With the increasing recrystallization annealing time, the average grain size of Mg-2%Nd alloys increased from 10μm to 30μm, and the RE texture strengthened gradually;(2) The addition of Dy blocked the processing of dynamic recrystallization, and the textures were <10-10> fibrous textures with high strength. After further recrystallization annealing, <10-10> fibrous textures were displaced by <40-41> fibrous textures (the angle of ED and <10-10> is about 65°) and <52-70> fibrous textures (the angle of ED and <10-10> is about 15°);(3) The elongation increased with the addition of Dy. The tensile strength reached 180MPa and elongation rate reached 24.72% when the addition of Dy was 5 wt.%, showing that the alloys had good combined properties.(4) The dynamic recrystallization process was blocked by the addition of Er element, and the structures were composed of {0001}//ED texture and RE-texture. After further recrystallization annealing, {0001}//ED texture developed into RE-texture.(5) Mg-6.0wt.%Er alloy had good plasticity at room temperature.Its elongation reached 29%, and the compression fracture true strain reached 0.55, but the yield strength was lower than pure magnesium;(6) It was indicated that Er element could improve the plasticity of magnesium at room temperature. On the one hand, it promoted the basal slip by changing textures, on the other hand, it improved the ability of dislocation slipping.