Abstract:

The contact characteristics and wear properties of Si₃N₄ high temperature resistant all ceramic radial spherical plain bearings were studied under high temperature conditions. Based on thermal-mechanics coupling finite element simulation method， the temperature fields of the inner and outer rings of the spherical plain bearings were analyzed. The wear tests were carried out by using self-developed high-temperature spherical plain bearing test machine. The wear surface morphology and composition of different contact areas of inner and outer rings were analyzed by scanning electron microscope and energy dispersive spectrometer， and the wear mechanism of all ceramic spherical plain bearings was proved. Results show that the wear processs of all ceramic spherical plain bearings at 400 °C are mainly divided into a running-in period with a significant increase in wear and a stable wear period with a slow increase in wear. The wear areas are mainly divided into core bearing areas dominated by adhesive wear and oxidation wear， and non-core bearing areas dominated by abrasive wear. The wear loss of the spherical plain bearings is as 108 μm under the condition of 200 N radial load， 2 Hz swing frequency and ±25° swing angle， 25 000 swing times. The wear resistance is good and the running state is stable.

Key words: Si₃N₄ ceramics, spherical plain bearing, high temperature environment, thermo-mechanics coupling, wear mechanism

摘要：

针对高温工况下Si₃N₄耐高温全陶瓷向心关节轴承的接触特性和磨损性能进行研究。基于热力耦合有限元仿真方式对关节轴承内外圈温度场进行分析，利用自研的高温关节轴承试验机开展磨损试验，通过扫描电子显微镜和能谱仪对内外圈不同接触区域的磨损表面形貌和成分进行分析，探明全陶瓷关节轴承的磨损机理。结果表明：全陶瓷关节轴承在400 ℃高温下，磨损过程主要分为磨损量显著增大的磨合期、磨损量缓慢增大的稳定磨损期；磨损区域主要分为以黏着磨损和氧化磨损为主的核心承压区、以磨粒磨损为主的非核心承压区。该关节轴承在200 N径向载荷、2 Hz摆动频率、±25°摆动角度、25 000次摆动条件下磨损量为108 μm，耐磨性能良好，运行状态平稳。

关键词: Si₃N₄陶瓷, 向心关节轴承, 高温环境, 热力耦合, 磨损机理