汽车发动机用AX55-xSn合金的热处理与蠕变性能  

Heat Treatment and Creep Property of AX55-xSn Alloy for Automotive Engine

作　　者：王瑞[1] 张丽凤[1] 王社则 罗峰 WANG Rui;ZHANG Lifeng;WANG Sheze;LUO Feng(Shanxi Traffic Vocational and Technical College,Taiyuan Shanxi 030031,China;Taiyuan University of Technology,Taiyuan Shanxi 030024,China)

机构地区：[1]山西交通职业技术学院,山西太原030031 [2]太原理工大学,山西太原030024

出　　处：《上海金属》2019年第5期47-52,共6页Shanghai Metals

基　　金：国家重点研发计划(No.2016YFB0301001);山西省重点研发计划(No.2017KKJH)

摘　　要：采用X射线衍射仪(XRD)、扫描电镜(SEM)和高温蠕变持久试验机等试验手段,研究了Sn含量和固溶时效工艺对AX55-x Sn(x=0,0.5,1,1.5)合金物相组成、显微组织、硬度和蠕变性能的影响。结果表明:添加Sn元素后,AX55-x Sn合金中除含α-Mg、Al 2Ca和(Mg,Al)2Ca相外,还出现了CaMgSn相;随着Sn含量的增加,双级固溶+时效和单级固溶+时效态AX55-x Sn合金的硬度都逐渐升高,相同Sn含量下单级固溶+时效态AX55-x Sn合金的显微硬度要高于双级固溶+时效态AX55-x Sn合金;随着Sn含量的增加,AX55-x Sn合金的总蠕变量和最小蠕变速率都逐渐减小,相同Sn含量下单级固溶+时效态AX55-x Sn合金的总蠕变量和最小蠕变速率相比双级固溶+时效态合金的小,说明具有更好的蠕变性能。AX55-1.5Sn合金的蠕变性能略低于高压压铸成型MRI230D合金,但明显高于Mg-4Al-2RE-2Ca合金,适用于制造汽车动力系统的零件。Effects of Sn contents and solution treating and aging processes on phase composition,microstructure,hardness and creep property of AX55-x Sn(x=0,0.5,1,1.5)alloy were studied by means of X-ray diffraction(XRD),scanning electron microscopy(SEM)and high temperature creep rupture tester.The results showed that CaMgSn phase appeared besidesα-Mg,Al 2Ca and(Mg,Al)2Ca phases in AX55-x Sn alloys after adding Sn element.With the increase of Sn content,the hardness of two-stage solution treated and aged as well as single-stage solution treated and aged AX55-x Sn alloys increased gradually,and the microhardness of single-stage solution treated and aged AX55-x Sn alloy was higher than that of two-stage solution treated and aged AX55-x Sn alloy with the same Sn content.With the increase of Sn content,the total creep amount and minimum creep rate of AX55-x Sn alloy decreased gradually.The total creep amount and minimum creep rate of single-stage solution treated and aged AX55-x Sn alloy were smaller than those of two-stage solution treated and aged alloy with the same Sn content,indiacting better creep property.The creep property of AX55-1.5Sn alloy was slightly lower than that of high pressure die cast MRI230D alloy,but significantly higher than that of Mg-4Al-2RE-2Ca alloy,being suitable for manufacturing parts of automotive power system.

关 键 词：AX55合金 锡 热处理 显微组织 蠕变性能 

分 类 号：TG1[金属学及工艺—金属学]