摘要
以Mo、Ni和Si金属粉末为原料，利用激光熔化沉积技术制备Mo基固溶体（Moss）增韧Mo2Ni，Si金属硅化物耐磨材料，在销-盘式摩擦磨损试验机上评价合金在400～550℃范围内的磨损性能，借助扫描电子显微镜观察合金磨损表面及其亚表面形貌．结果表明，Moss增韧Mo2Ni3Si金属硅化物合金在高温滑动条件下表现出反常的磨损率一温度关系，即磨损率随温度的升高而降低，其磨损表面光滑平整，没有显微切削和犁沟等特征，Moss树枝晶在试验温度下发生了轻微氧化．金属硅化物Mo2Ni3Si在磨损过程中起到了抗磨作用，韧性良好的Moss树枝晶有效地抑制了Mo2Ni3Si基体的裂纹扩展和显微剥落．合金在高温滑动条件下的主要磨损机理为软磨粒磨损和Moss相的轻微氧化．
Commercially pure molybdenum, nickel and silicon elemental powders were selected as raw materials. Mo2Ni3Si alloy consisting of molybdenum-based solid solution （ Moss ） primary dendrites and ternary metal silicide Mo2Ni3Si matrix was fabricated using laser melting deposition manufacturing process. Wear resistance of the alloy was evaluated on a pin-on-disc tester in the range of 400 -550 ℃. The morphologies of worn surface and subsurface was characterized by SEM. Results showed that the Moss-toughened Mo2Ni3 Si alloy exhibits abnormal dependence of wear on temperature, which is that wear rate decreased as temperature increased. The worn surface of the alloy was very smooth and clear without any characteristics of micro-cutting and plowing. Slight oxidation of Moss dendrites was observed on the worn surfaces in the test temperatures. Mo2Ni3Si ternary metal silicide played domi- nant role in resisting the wear. Propagation of micro-cracks and micro-spalling in the Mo2Ni3Si matrix were restrain- ed by the ductile Moss dendrites. The main failure mechanisms of the Moss-toughened Mo2Ni3Si alloy under elevated-temperature sliding wear were soft abrasion and slight oxidation of Moss phase.
出处
《摩擦学学报》
EI
CAS
CSCD
北大核心
2007年第5期416-420,共5页
Tribology
基金
国家杰出青年科学基金资助项目(50625413)
