In order to examine the effect of sliding speeds on the elevated temperature tribological performance of atmospheric plasma-sprayed Ni-Al-Ag-MoS 2 (NAMB), Ni-Al-Ag-MoS 2 -5 wt.% hBN (NAMB5) and Ni-Al-Ag-MoS 2 -10 wt.% hBN (NAMB10) composite coatings, friction and wear tests were conducted against alumina ball as a counter face using ‘a rotary ball on disk configuration’ at a constant load of 5 N and different sliding speeds 0.3, 0.5, 0.7 and 0.9 m/s from room temperature (RT) to 800 °C using a high-temperature tribometer. Both coefficient of friction and wear rate were found to decrease with increasing speed from 0.3 to 0.7 m/s with a marginal increase beyond that for all the coatings. However, coating NAMB5 exhibited better lubricity in comparison with the other coatings at all sliding speeds and temperatures. The coefficient of friction recorded for this coating decreased from 0.51 to 0.23 at a sliding speed of 0.3 m/s and from 0.48 to 0.1 at a sliding speed of 0.7 m/s as the temperature was increased from RT to 800 °C. The results indicate the existence of a synergistic action of hBN in combination with Ag and MoS 2 in providing lower friction and wear, thus highlighting the potential of hBN as an effective solid lubricant to stabilize the friction in a wide range of temperatures and speeds.

中文翻译：

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大气等离子喷涂沉积镍基复合涂层在不同速度和温度下的摩擦学行为

为了检查滑动速度对常压等离子喷涂 Ni-Al-Ag-MoS 2 (NAMB)、Ni-Al-Ag-MoS 2 -5 wt.% hBN (NAMB5) 和Ni-Al-Ag-MoS 2 -10 wt.% hBN (NAMB10) 复合涂层、摩擦和磨损测试是在 5 N 的恒定负载下使用“圆盘上的旋转球配置”以氧化铝球为反面进行的，并且使用高温摩擦计从室温 (RT) 到 800 °C 的不同滑动速度为 0.3、0.5、0.7 和 0.9 m/s。发现摩擦系数和磨损率都随着速度从 0.3 增加到 0.7 m/s 而降低，所有涂层的边际增加都超过了这一点。然而，与其他涂层相比，NAMB5 涂层在所有滑动速度和温度下都表现出更好的润滑性。随着温度从室温升高到 800°C，该涂层的摩擦系数在 0.3 m/s 的滑动速度下从 0.51 下降到 0.23，在 0.7 m/s 的滑动速度下从 0.48 下降到 0.1。结果表明 hBN 与 Ag 和 MoS 2 的组合在提供较低的摩擦和磨损方面存在协同作用，从而突出了 hBN 作为有效固体润滑剂在广泛的温度和速度范围内稳定摩擦的潜力。