挤锻复合成形AZ80镁合金的组织与冲击性能研究  

Investigation on microstructure and impact properties of magnesium alloy AZ80 by extrusion-forging compound forming

作　　者：吴思俊[1] 张宇[2] Wu Sijun;Zhang Yu(School of Electrical and Electronic Engineering,Zhejiang Industry Polytechnic College,Shaoxing 312000;School of Mechanical Engineering,Zhejiang Industry Polytechnic College,Shaoxing 312000,China)

机构地区：[1]浙江工业职业技术学院电气电子工程学院,浙江绍兴312000 [2]浙江工业职业技术学院机械工程学院,浙江绍兴312000

出　　处：《锻压技术》2018年第8期173-177,共5页Forging & Stamping Technology

基　　金：浙江省公益技术应用研究计划项目(2017C31039)

摘　　要：采用不同的工艺参数对AZ80镁合金进行了挤锻复合成形,研究了挤压温度、锻压温度对合金显微组织和冲击性能的影响。试验结果表明：随挤压温度、锻压温度增加,AZ80镁合金的平均晶粒尺寸均先减小后增大,冲击韧度均先增大后减小。当挤压温度和锻压温度均为390℃时,AZ80镁合金的平均晶粒尺寸最小,晶粒得到显著细化,冲击韧度最大,韧性最佳,冲击性能最好。挤压温度和锻压温度的升高能够激活和协调镁合金的棱柱滑移系,减小变形的阻力,进而提升镁合金内部组织的塑性变形。挤锻复合成形有利于AZ80镁合金的塑性变形,晶粒的细化和均匀化分布使得裂纹难以产生,而且第二相的分布状态也使得裂纹难以蔓延,因此经挤压后的镁合金韧性较佳。当挤压温度或锻压温度继续上升至420℃后,镁合金内部的强化相晶粒反而增大,冲击韧度变小,冲击性能下降。The extrusion-forging compound forming of magnesium alloy AZ80 was conducted by different process parameters,and the influences of extrusion temperature and forging temperature on the microstructure and impact properties of alloy were studied. The experimental results show that the average grain size of magnesium alloy AZ80 decreases first and then increases and the impact toughness increases first and then decreases with the increasing of extrusion temperature and forging temperature. When the extrusion temperature and forging temperature are 390 ℃,the average grain size of magnesium alloy AZ80 is the smallest and the impact toughness is the highest,so the grain is significantly refined and the best toughness and impact performance are obtained. Therefore,the increase of extrusion temperature and forging temperature can activate and coordinate the prismatic slip system of magnesium alloy to reduce the resistance of deformation,and then the plastic deformation of the internal structure of magnesium alloy is enhanced. The extrusion-forging compound forming is beneficial to the plastic deformation of magnesium alloy AZ80,the grain refinement and homogenization distribution are difficult to produce the crack,and the distribution of the second phase is also difficult to propagate the crack. Thus,the toughness of the extruded magnesium alloy becomes better. When the extrusion temperature or forging temperature rise to 420 ℃ continually,the size of reinforcement grain inside the magnesium alloy increases,the impact toughness decreases,and the impact properties decrease.

关 键 词：AZ80镁合金 挤锻复合成形 显微组织 冲击性能 挤压温度 锻压温度 

分 类 号：TG249.2[金属学及工艺—铸造]