Mg-7Sn-Zn(Y)合金的显微组织、时效硬化行为及力学性能  

Microstructure,age-hardening behavior and mechanical properties of Mg-7Sn-Zn(Y)alloy

作　　者：毕广利[1] 徐作成 顾家睿 姜静[1] 蒋春宏 李元东[1] BI Guang-li;XU Zuo-cheng;GU Jia-rui;JIANG Jing;JIANG Chun-hong;LI Yuan-dong(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou Univ. of Tech., Lanzhou 730050, China;Lanshi Foundry Co., Ltd., Lanzhou 730050, China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [2]兰石铸造有限公司,甘肃兰州730050

出　　处：《兰州理工大学学报》2020年第6期1-8,共8页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51961021);甘肃省自然科学基金(18JR3RA138);大学生创新创业计划(DC2018022,DC2019158,DC2019186)。

摘　　要：研究了Zn和Y合金化对Mg-7Sn合金显微组织、时效硬化行为和力学性能的影响.铸态Mg-7Sn合金主要由α-Mg和共晶(α-Mg+Mg2Sn)相组成.Zn添加细化了Mg2Sn相的尺寸,促进了Mg2Sn相大量、均匀的弥散分布,同时诱导了Mg2Sn相的非基面析出,增强了合金时效硬化效果.合金时效峰值硬度从64.6 HV增大到69.7 HV,峰值时效时间从166 h缩小至142 h.Zn和Y元素共同添加形成了针状MgSnY相,有效缩短了合金的时效峰值时间(由166 h缩短至120 h),但合金的峰值硬度略有降低,Mg-7Sn-1Zn合金具有最佳的力学性能,其高力学性能主要归结为细小、高体积分数Mg2Sn相的析出强化.The microstructure,age-hardening behavior and mechanical properties of Mg-7Sn-Zn(Y)alloy were investigated.The as-cast Mg-7Sn alloy was mainly composed ofα-Mg and eutectic(α-Mg+Mg2Sn)phase.The addition of Zn refines Mg2Sn phase,increases volume fraction of Mg2Sn phase and promotes precipitation of Mg2Sn phase on non-basal plane,and thus enhances the ageing hardening capacity of the alloy.The peak-ageing hardness of the Mg-7Sn-1Zn alloy increases from 64.6 HV to 69.7 HV,and the peak-ageing time decreases from 166 h to 142 h.The addition of Zn and Y elements forms the needlelike MgSnY phase.Although the peak-ageing time of the alloy is effectively decreased(166 h to 120 h),the peak-ageing hardness of the alloy reduces.The Mg-7Sn-1Zn alloy exhibits the best mechanical properties,Which was mainly attributed to the precipitation strengthening of fine Mg2Sn phase with high volume fraction.

关 键 词：Mg-Sn-Zn-Y合金 显微组织 时效硬化行为 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]