热挤压AZ80镁合金管材的组织与力学性能

Microstructure and mechanical properties of hot extruded tube of AZ80 magnesium alloy

对AZ80镁合金管材的挤压工艺进行研究,对挤压前后材料的组织与力学性能进行分析。结果表明,经过热挤压后,镁合金的晶粒细化,力学性能有较大提高。晶粒尺寸由挤压前铸态的28μm细化到挤压后的4μm,抗拉强度由162 MPa提高到265 MPa,屈服强度由74 MPa提高到180 MPa,伸长率由4%提高到14%。随着挤压比的增加,晶粒细化明显,伸长率和屈服强度增加。对于挤压AZ80镁合金管材,合理的挤压工艺参数：挤压比为18.2,坯料温度为390℃,模具预热温度为360℃,挤压速度为1 mm/s,凹模锥半角为60°-70°。

Extrusion technology of magnesium alloy AZ80 tube was studied.The microstructure and mechanical properties of extruded tube of the alloy were analyzed.The results show that the material grain size is refined by hot extrusion,and the mechanical properties are increased.The grain size of the alloy tube is changed from 28 μm as casting to 4 μm as extruded.Tensile strength is changed from 162 MPa to 265 MPa,and yield strength is from 74 MPa to 180 MPa,and elongation is from 4% to 14%.With the increasing of extrusion ratio,the grain size is refined significantly and the elongation and yield strength are increased.The suitable extrusion parameters of the alloy tube are that extrusion ratio is 18.2,forming temperature is 390 ℃,die preheating temperature is 360 ℃,conical semi-angle of fovea die is 60°-70°,and extrusion speed is 1 mm/s.