挤压温度对固相再生ZM6镁合金组织和性能的影响

利用固相再生方法在挤压比为25：1的条件下，将ZM6镁合金屑分别在350℃、400℃、450℃和500℃温度下制备成试样，进行微观组织观察和力学性能测试。结果表明：当挤压温度为400℃时，ZM6耐热镁合金没有发生再结晶，合金中金属化合物在挤压过程中被打碎，均匀分布在基体中；当挤压温度为450℃和500℃时，ZM6镁合金发生部分动态再结晶；随着挤压温度的提高，合金的抗拉强度和延伸率提高；在挤压温度为500℃，合金的抗拉强度、屈服强度和延伸率分别为300．2MPa、142．9MPa和30％。合金室温拉伸断口主要表现为穿晶韧窝断裂。

Effect of extrusion temperature on microstructure and mechanical properties of ZM6 magnesium alloys prepared by a solid recycling process

ZM6 magnesium alloy was prepared by hot extrusion of machined chips at 350℃,400℃,450℃ and 500 ℃ with an extrusion ratio of 25 ： 1; subsequently its microstructure and mechanical properties were investigated. The results indicate： some coarse intermetallie phases of the alloy were broken into small particles and moved from grain boundaries to grain interiors during the hot extrusion process. A large number of small particles were dispersed in the matrix of the magnesium alloys. The samples that were extruded at 450 ℃ and 500℃ exhibit partial dynamic recrystallization. Tensile strength is greatly improved and elongation increases with the extruding temperature increasing. The ultimate tensile strength, 0. 2% proof stress and the elongation of ZM6 magnesium alloys extruded at 500 ℃ are 300. 2 MPa, 142. 9 MPa and 30%, respectively. Fracture mode of the alloy was transgranular dimple fracture.