快速凝固Mg-Si-RE(Ce,La)镁合金的微观组织及其摩擦磨损行为  

Microstructure and Friction and Wear Behavior of Rapidly Solidified Mg-Si-RE(Ce,La) Magnesium Alloys

作　　者：李瑶辉 李克[1] 尹文来 戴佳 Li Yaohui;Li Ke;Yin Wenlai;Dai Jia(School of Mechanical and Electrical Engineering,Nanchang University,Nanchang 330031,China)

机构地区：[1]南昌大学机电工程学院,江西南昌330031

出　　处：《稀有金属材料与工程》2022年第1期266-272,共7页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(52061031,51665036)。

摘　　要：利用快速凝固工艺(RSP)制备了Mg-Si-RE镁合金并对其显微组织及在不同载荷下的摩擦磨损行为和磨损机制进行分析。研究发现,快速凝固Mg-Si-RE合金的显微组织主要由α-Mg基体、Mg2Si共晶相和REMg2Si2纳米稀土相组成。对摩擦系数和磨损量随载荷变化的关系曲线分析表明,Mg-Si-RE合金的耐摩擦磨损性能明显优于Mg-1Si基体合金,由轻微磨损转变为严重磨损时的载荷比基体合金高20N,且在高载荷时磨损量远远小于基体合金,120N时的磨损量仅为基体合金的50%。Mg-Si-RE合金的磨损机制包括氧化磨损、磨粒磨损和剥层磨损,其优异的耐摩擦磨损性能主要归功于析出了弥散分布在晶界和晶内的纳米稀土相。同时,稀土元素能对镁合金基体起到固溶强化作用,有效提高了Mg-Si-RE合金的耐摩擦磨损性能。实验还发现加入不同种类的稀土元素后,Mg-Si-RE合金表现出不同的摩擦磨损行为。Microstructure, friction and wear behavior and wear mechanism under different loads of Mg-Si-RE magnesium alloys fabricated by rapidly-solidified process were studied. It is found that the microstructure of the rapidly-solidified Mg-Si-RE alloy mainly consists of α-Mg matrix, eutectic Mg2 Si phases and REMg2 Si2 nano phases with size of 500~800 nm. The relationship curves between friction coefficient and wear mass loss with load of Mg-Si-RE alloy was determined. Results show that the friction and wear resistance of Mg-Si-RE alloy is obviously better than that of Mg-1 Si matrix alloy. The load under which the wear mode of Mg-Si-RE alloy changes from slight wear to serious wear is 20 N higher than that applied to matrix alloy. The wear mass loss is much smaller than that of matrix alloy at high load, and the wear mass loss at 120 N is only 50% of matrix alloy. The wear mechanism of Mg-Si-RE alloy includes oxidation wear,abrasive wear and delamination wear. The excellent friction and wear resistance of RSP Mg-Si-RE alloy is mainly due to the nano-scale rare earth phases well dispersed along the grain boundary and within α-Mg matrix. At the same time, rare earth elements play a solid solution strengthening effect on Mg alloy matrix, effectively improving the friction and wear resistance of Mg-Si-RE alloy. Moreover, the Mg-Si-RE alloys exhibit different friction and wear behaviors after the addition of different types of rare earth elements.

关 键 词：镁合金 耐摩擦磨损性能 纳米稀土相 磨损机制 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG294[金属学及工艺—金属材料]