VN-Ag-MoO3复合材料的制备及宽温域摩擦学行为

利用真空热压烧结技术制备了VN-Ag-MoO₃复合材料，研究了Ag₂MoO₄对VN基复合材料组织结构及宽温域摩擦磨损性能的影响。结果表明:VN-Ag-MoO₃复合材料组织较致密，主要由VN、MoO₃和Ag组成，其中均匀分布于VN基体的MoO₃和Ag由Ag₂MoO₄经高温分解形成。宽温域摩擦磨损测试表明，Ag₂MoO₄的添加有效改善了室温(RT)~700℃温域范围VN陶瓷的摩擦磨损性能。其中，700℃时Ag₂MoO₄含量为10wt%的VN-10Ag-MoO₃的摩擦系数(0.285)和磨损率(1.37×10?5 mm3/(N·m))分别较VN降低了23%和72%，这归因于磨损表面的氧化钒、钒酸银和钼酸银等高温润滑相起到了优异的润滑及减磨作用。 

Preparation and wide temperature range tribological behavior of VN-Ag-MoO3 composites

VN-Ag-MoO₃ composites were prepared by vacuum hot pressing sintering. The effects of Ag₂MoO₄ on the microstructure and wide temperature range friction and wear properties of VN matrix composites were investigated. The results show that the structure of VN-Ag-MoO₃ composite is relatively compact, mainly composed of VN, MoO₃ and Ag, and the MoO₃ and Ag distributed evenly in VN matrix are formed by the decomposition of Ag₂MoO₄ at high temperature. Friction and wear tests in a wide temperature range show that the addition of Ag₂MoO₄ can effectively improve the friction and wear properties of VN ceramics in the temperature range of room temperature (RT)-700℃. The friction coefficient (0.285) and wear rate (1.37×10?5 mm3/(N·m)) of VN-10Ag-MoO₃ with 10wt% Ag₂MoO₄ at 700℃ are 23% and 72% lower than those of VN, respectively, which are attributed to the excellent lubrication and wear reduction effects of high temperature lubrication phases such as vanadium oxide, silver vanadate and silver molybdate on the wear surface.