【摘要】 通过高能球磨和真空热压烧结技术制备了NiCrMoAlAg合金和NiCrMoAlAg-Al₂O₃复合材料。研究了Al₂O₃对NiCrMoAlAg-Al₂O₃复合材料的微观组织结构和机械性能的影响,考察了复合材料室温至800℃下的摩擦磨损性能并探究其磨损机理。结果表明:NiCrMoAlAg-Al₂O₃复合材料主要由镍基固溶体、Ag、Al的氧化物和微量γ"相组成;随着Al₂O₃加入,复合材料密度降低,但硬度、抗拉强度和抗压强度提高;NiCrMoAlAg-Al₂O₃复合材料摩擦系数随温度的升高逐渐减小,磨损率随着温度的升高先增大后减小;通过SEM及Raman分析发现,在600℃及以上摩擦过程中磨损表面形成了一层由NiO、MoO₂、MoO₃和Ag₂MoO₄等组成的润滑膜,从而降低了材料的摩擦系数和磨损率。更多还原

【Abstract】 Two different materials of NiCrMoAlAg alloy and NiCrMoAlAg-Al₂O₃ composite were prepared by high-energy ball milling and vacuum hot press sintering technology.The effects of Al₂O₃ on the microstructure and mechanical properties of NiCrMoAlAg-Al₂O₃ composite were studied.The friction and wear properties of the composite and the wear mechanism were investigated from room temperature to 800 ℃.The results show that the NiCrMoAlAg-Al₂O₃ composite is mainly composed of Ni-based solution,Ag,Al₂O₃ and traceγ" phase.With the addition of Al₂O₃,the density of the composite decreases,but the hardness,tensile strength and compressive strength of the composite increase.The friction coefficient of NiCrMoAlAg-Al₂O₃ composite decreases with increasing of temperature,and the wear rates increases firstly and then decreases with increasing of temperature.SEM and Raman analysis show that a lubricating film composed of NiO,MoO₂,MoO₃ and Ag₂ MoO₄ is formed on the worn surface during the friction process at 600℃and above,which reduces the friction coefficient and wear rate of the composite at high temperature.更多还原