Cui Gongjun, Liu Yanping, Gao Guijun, Liu Huiqiang, Kou Ziming
College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
National-Local Joint Laboratory of Mining Fluid Control Engineering, Taiyuan 030024, China.
Materials (Basel). 2019 Dec 20;13(1):51. doi: 10.3390/ma13010051.
FeCr matrix high-temperature self-lubricating composites reinforced by Mo, Ag, and CuO were fabricated by the powder metallurgy technique. The tribological behaviors of composites were studied at temperatures up to 800 °C. The CuO content was optimized according to the tribological results. Mo showed an obvious lubricating effect when it converted into MoO. The bimetallic oxide system formed high-temperature solid lubricants with low shear strength. CuO reacted with MoO and formed CuMoO and CuMoO. The composites showed an increase in the friction coefficient with the increase of CuO. However, the wear rates decreased with the increase of CuO. The critical threshold at which there was a transition of friction coefficients and wear rates from room temperature (RT) to 800 °C was 10 wt.% CuO. The Fe(Cr)-14% Mo-10.5% Ag-10% CuO composite showed the most reasonable high-temperature tribological behaviors. This was ascribed to the synergistic effects of silver, Mo, in situ formed solid lubricants (metal oxides and salt compounds), and the stable oxide film on the worn surfaces. At elevated temperatures, the dominant wear mechanism was oxidation wear.
采用粉末冶金技术制备了由Mo、Ag和CuO增强的FeCr基高温自润滑复合材料。研究了复合材料在高达800℃温度下的摩擦学行为。根据摩擦学结果对CuO含量进行了优化。Mo转化为MoO时显示出明显的润滑效果。双金属氧化物体系形成了具有低剪切强度的高温固体润滑剂。CuO与MoO反应形成了CuMoO和CuMoO。复合材料的摩擦系数随CuO含量的增加而增大。然而，磨损率随CuO含量的增加而降低。摩擦系数和磨损率从室温（RT）到800℃发生转变的临界阈值为10 wt.% CuO。Fe(Cr)-14% Mo-10.5% Ag-10% CuO复合材料表现出最合理的高温摩擦学行为。这归因于银、Mo、原位形成的固体润滑剂（金属氧化物和盐化合物）以及磨损表面上稳定的氧化膜的协同作用。在高温下，主要的磨损机制是氧化磨损。
