Friction and wear behavior of Ni-based solid-lubricating composites at high temperature in a vacuum environment

Publication date: 15 May 2017
Source:Materials & Design, Volume 122
Author(s): Jun Cheng, Jinming Zhen, Shengyu Zhu, Jun Yang, Jiqiang Ma, Wensheng Li, Weimin Liu
In this paper, the effect of the complex condition with high temperature and vacuum on the tribological properties of NiCrMoAl-Ag-CaF2/BaF2 solid-lubricating composite has been investigated. It presents that this composite displays the excellent tribological properties in vacuum than in air from room temperature to 800°C. In vacuum, the friction coefficients are around or below 0.20 and superior to that in air. Besides, the wear rates in vacuum are at least one order of magnitude lower than those tested in air. They can be divided into three stages with the temperature (10⁻⁷mm³/Nm at room temperature and 200°C, 10⁻⁶mm³/Nm between 400 and 600°C, and 10⁻⁵mm³/Nm at 800°C). Also, the surface oxidation behavior and the lubrication characteristics of solid lubricants (Ag and fluorides) in vacuum are clarified and related to the tribological properties.

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