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研究了在230℃时效不同时间对Mg-5Sn-Mn合金热导率及力学性能的影响。结果表明:Mg-5Sn-Mn合金主要由α-Mg基体和Mg_2Sn相组成,且第二相分布在晶界上,经固溶处理后这些Mg_2Sn全部溶解,形成α-Mg固溶体。在时效过程中,Mg_2Sn先在晶界断续析出,然后在基体晶粒内部析出大量弥散的Mg_2Sn细小颗粒,随着时效时间的延长,颗粒逐渐长大。合金的热导率呈先上升后下降趋势,并且在时效144 h时达到最大值103.5 W·m~(-1)·K~(-1);硬度在时效72 h后达到最大值54 HBW,抗拉强度和伸长率在时效120 h分别达到最大值161 MPa和8.1%。
The effects of different aging time at 230 ℃ on the thermal conductivity and mechanical properties of Mg-5Sn-Mn alloy were studied. The results show that the Mg-5Sn-Mn alloy is mainly composed of α-Mg matrix and Mg_2Sn phase, and the second phase is distributed on the grain boundary. All these Mg_2Sn are dissolved by solution treatment to form α-Mg solid solution. During the aging process, Mg_2Sn precipitates first at the grain boundaries, and then a large amount of Mg_2Sn fine particles are precipitated in the matrix grains. With the aging time increasing, the particles gradually grow up. The thermal conductivity of the alloy first increased and then decreased, and reached the maximum of 103.5 W · m -1 K -1 at 144 h after aging. The hardness reached the maximum of 54 HBW after 72 h aging, Tensile strength and elongation reached the maximum of 161 MPa and 8.1% respectively at 120 h after aging.