Mg_2Si_(1-x)Sn_x合金的组织和性能  

Microstructure and performance of alloy Mg_2Si_(1-x)Sn_x

作　　者：周琦[1] 臧树俊[1] 李延荣[1] ZHOU Qi;ZANG Shu-jun;LI Yan-rong(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou Univ.of Tech.,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

出　　处：《兰州理工大学学报》2018年第2期1-6,共6页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(51001057);甘肃省自然科学基金(1610RJZA010)

摘　　要：采用机械合金化+热压烧结制备Mg_2Si_(1-x)Sn_x(x=0、0.2、0.4、0.6、0.8)合金,对合金的组织性能进行了研究.结果表明:Mg2Si中的部分Si被Sn替代,晶体结构并不发生改变.随Sn替代量的增加,合金的点阵常数逐渐增大,整个XRD衍射峰向低角偏移增大,致密度先增大后减小,晶粒得到细化.随Sn替代量的增加,合金的抗压强度、抗弯强度先增大后减小,断裂方式由解理断裂向准解理断裂转变;引入Sn元素,Mg2Si1-xSnx的力学性能和热电性能得到提高,当x=0.4时,合金具有最佳的综合性能.合金的强化是由细晶强化、固溶强化和第二相强化3种机制共同作用的结果.Alloy Mg 2Si 1-x Sn x(x=0、0.2、0.4、0.6、0.8)was prepared by means of mechanical alloying combined with hot-press sintering,and the microstructure and performance of the alloy were studied.The result showed that although a portion of Si in Mg 2Si was substituted by Sn,the crystalline structure of the intermetallics would not change.With the increasing of Sn substitute amount,the lattice constant would increase gradually,the shift of the overall XRD diffraction peaks toward lower angles would increase and the compactedness would increase at first and then decrease,making the grain size of the alloy fine.At the same time,the compressive strength and bending strength of the alloy would increase at first and then decrease,and the fracture morphology would be transformed from cleavage rupture into quasi-cleavage rupture.Adding the Sn element could improve mechanical and thermoelectric properties of alloy Mg 2Si 1-x Sn x and when x=0.4,the alloy would exhibit optimal comprehensive performance.It could be concluded that the strengthening of the alloy was the result of a combined effect of such three mechanisms as grain-refinement strengthening,solid-solution strengthening,and second phase strengthening.

关 键 词：Mg2Si1-xSnx合金 组织 性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]