摘要
利用SEM、XRD、硬度及力学性能测试,研究了Mg-8Zn-1.5Sm合金400℃固溶处理后的显微组织和力学性能。结果表明：合金固溶处理后主要成分Mg2Zn3与Mg41Sm5明显增多。随固溶处理时间增加,原先的α-Mg枝晶结构的数量不断减少并转变成块状组织;当固溶时间达到20 h后,合金中的枝晶组织已经完全消失。随固溶时间的上升,合金拉伸强度、伸长率与硬度均表现出先增强后减弱的变化,在20 h时,分别达到256 MPa、13.6%与76.4 HV。铸态合金的拉伸断口形貌表现为晶界断裂类型。随固溶时间的增加,合金解理刻面及撕裂棱增多,合金断口特点从沿晶断裂转化成韧性断裂。
The microstructure and mechanical properties of Mg-8 Zn-1.5 Sm alloy after solution treatment at 400 ℃ were studied by means of SEM, XRD, hardness and mechanical properties test. The results show that, the alloy ingredients Mg2 Zn3 and Mg41 Sm5 increase obviously after solid solution treatment. With the increase of solution treatment time, the number ofα-Mg dendritic structure decreases and changes into bulk microstructure. When the solution time reaches 20 h, the dendritic structure of the alloy can completely disappear. With the increase of solution time, the tensile strength, elongation and hardness of the alloy increase firstly and then decrease, reaching 256 MPa, 13.6% and 76.4 HV at 20 h, respectively. The tensile fracture morphology of cast alloy is characterized by grain boundary fracture type. With the increase of solution time,the cleavage surface and tearing edge of the alloy increase, and the fracture characteristics of the alloy change from intergranular fracture to ductile fracture.
作者
孙瑞霞
刘义付
王瑞红
李雪
马利华
SUN Ruixia;LIU Yifu;WANG Ruihong;LI Xue;MA Lihua(School of Automotive Engineering,Huanghe Jiaotong University,Jiaozuo 454950,China)
出处
《热加工工艺》
CSCD
北大核心
2018年第20期222-224,227,共4页
Hot Working Technology
