Ca对高Zn镁合金高温抗蠕变性能的影响  

Effects of Calcium Addition on High Temperature Creep Resistance of Magnesium Alloys with High Zinc

作　　者：万晓峰[1] 孙扬善[1,2] 薛烽[1,2] 白晶[1,2] 陶卫建 

机构地区：[1]东南大学,江苏南京211189 [2]江苏省先进金属材料高技术研究重点实验室,江苏南京211189 [3]江苏省镁合金材料工程技术研究中心,江苏南京211224

出　　处：《稀有金属材料与工程》2010年第12期2112-2116,共5页Rare Metal Materials and Engineering

基　　金：国家科技支撑计划(2006BAE04B07)

摘　　要：系统研究了微量Ca的加入对Mg-12Zn-4Al-0.3Mn合金显微组织和高温抗蠕度性能的影响。结果表明,Mg-12Zn-4Al-0.3Mn铸造镁合金的显微组织主要由α-Mg基体和块状准晶晶界相组成,在成分上准晶相与三元平衡相图中τ相(Mg32(Al,Zn)49)接近。少量Ca加入母合金后,块状准晶相部分转变为τ相和层片状φ相(Al2Mg5Zn2)。随Ca加入量增加,φ相的体积分数增多。Ca的加入显著提高了合金高温抗蠕变性能,175℃,70MPa蠕变条件下,Ca加入量为0.6%时,合金呈现最好的蠕变抗力,其稳态蠕变速率比母合金下降了近一个数量级。The effects of trace Ca addition on microstructure and high-temperature creep resistance of as-cast Mg-12Zn-4Al-0.3Mn alloy were investigated. Results show that the as-cast microstructure of the base alloy consists of alpha-Mg matrix and block quasicrystalline phase at gain boundaries. The composition of this quasicrystalline phase is closed to that of the equilibrium tau phase (Mg(32)(Al,Zn)(49)) in the Mg-Zn-Al ternary system. A small amount of Ca addition to the base alloy results in the formation of a lamellar eutectic phi(Al(2)Mg(5)Zn(2)) and the transformation of the quasicrystalline phase to the equilibrium tau phase in the as-cast microstructure of the alloy. The volume fraction of the phi phase increases with the increase of Ca addition. The creep resistance of the alloys is significantly improved by Ca addition. The optimum creep resistance of the alloy is obtained by 0.6% Ca addition under the creep condition of 175 degrees C, 70 MPa, whose steady state creep rate is approximately one order of magnitude lower than that of its base alloy.

关 键 词：铸造镁合金 高温 抗蠕变性能 Zinc High Temperature Magnesium Alloys Creep Resistance 合金显微组织 准晶相 稳态蠕变速率 母合金 系统研究 体积分数 蠕变抗力 平衡相图 块状 相组成 变条件 微量 片状 

分 类 号：TG146.22[一般工业技术—材料科学与工程]