AZ61镁合金在不同挤压温度下的组织与力学性能

Effects of Varied Hot Extrusion Temperature on Microstructure and Mechanical Properties of AZ61 Magnesium Alloy

对变形镁合金AZ61铸态试样和不同温度下的挤压成形试样的微观组织结构、室温力学性能以及拉伸断口进行了研究。结果表明,360℃的热挤压温度不能成形试样,在370、385、400℃下进行热挤压可以得到外形完整、表面光洁的试样;随着挤压温度提高,AZ61挤压试样发生再结晶的晶粒数量显著增加,达到400℃时形成均匀细小的等轴晶组织;370、385、400℃下的挤压试样断口均表现为明显的塑性断裂特征,400℃时挤压试样的抗拉强度达到297.43MPa,屈服强度达到221.42MPa,伸长率为22.39%,具有较好的力学性能。

After homogenized annealing at(390±10)℃ for 12 hours,AZ61 alloy was hot extruded at 360,370,385 and 400℃ with extrusion ratio of 32:1.Microstructure,mechanical properties and tensile fracture of annealed specimens and hot extruded specimens were investigated.A complete and finished product can be obtained by extruding AZ61 magnesium alloy at 370,385 and 400 ℃,however,it can not be produced by extruding at 360 ℃.With increasing in extrusion temperature,the numbers of recrystallization grain in the extruded AZ61 magnesium alloy are increased greatly,in which the uniformly fine equaixed grain are observed in the extruded specimens at 400 ℃.In addition,the specimens extruded at 370,385 and 400 ℃ are characterized by ductile fracture mechanism,and the specimens extruded at 400 ℃ exhibits excellent performance with tensile strength of 297.43MPa,yield strength of 221.42 MPa and elongation of 22.39%.