Abstract

As a type of thermal structure ceramic, vanadium nitride (VN) ceramics are widely used in harsh conditions, such as high temperatures, variable temperatures, or oxidizing atmospheres. However, high friction coefficients and wear rates under wide temperature ranges limit the application of VN in moving parts. In this article, VN-based composites with different contents of MoS₂/Ag lubricants are prepared by vacuum hot-press sintering technology, and the microstructure and tribological behavior of VN-MoS₂/Ag composites over a wide temperature range are studied. The results show that sintered VN-based composites are composed of the VN phase and corresponding MoS₂/Ag lubricants, where MoS₂ and Ag are uniformly distributed in the VN matrix. The tribological behavior of VN-based composites confirms that the addition of MoS₂ lubricant significantly improves the friction coefficient of the VN ceramic at room temperature and 300 °C, whereas the MoS₂/Ag lubricants obviously decrease the friction coefficient of the VN ceramic at room temperature to 700 °C; in particular, the friction coefficient of the VN-MoS₂/Ag composites at 700 °C is lower than 0.17. Furthermore, the synergistic effect between MoS₂ and Ag lubricants is the key factor for the excellent friction coefficient and wear performance of VN-based composites over a wide temperature range.

摘要

氮化钒（VN）陶瓷作为一种热结构陶瓷，广泛应用于高温、变温或氧化气氛等恶劣条件下。然而，宽温度范围内的高摩擦系数和磨损率限制了 VN 在运动部件中的应用。本文采用真空热压烧结技术制备了不同含量MoS _{2 /Ag润滑剂的VN基复合材料，研究了VN-MoS 2} /Ag复合材料在较宽温度范围内的显微组织和摩擦学行为。结果表明，烧结VN基复合材料由VN相和相应的MoS ₂ /Ag润滑剂组成，其中MoS ₂和 Ag 均匀分布在 VN 矩阵中。VN基复合材料的摩擦学行为证实，MoS ₂润滑剂的加入显着提高了VN陶瓷在室温和300℃下的摩擦系数，而MoS ₂ /Ag润滑剂明显降低了VN陶瓷在室温和300℃下的摩擦系数。室温至 700 °C；_{特别是，VN-MoS 2} /Ag 复合材料在 700 ℃时的摩擦系数低于 0.17。_{此外，MoS 2}和Ag润滑剂之间的协同效应是VN基复合材料在宽温度范围内具有优异摩擦系数和耐磨性能的关键因素。