固体润滑国家重点实验室（LSL）知识库

Ni-based composites with in situ formed Al₂O₃ and TiC ceramic phases were fabricated by hot pressing technology and that with directly added Al₂O₃ and TiC particles (ex situ) were also fabricated for comparison. The antioxygenic property and tribological properties of the composites were comparatively studied. The results show that the high-temperature oxidation resistance of the composite with in situ formed Al₂O₃ and TiC ceramic is superior to that of ex situ composite, and the friction coefficient of in situ composite is lower than that of ex situ composite in the wide temperature range from 400 °C to 1000 °C. The lowest friction coefficient was about 0.19 at 1000 °C and the wear rate of the composites are in the order of magnitude of 10⁻⁶ mm³/(N m) at high temperatures. The differences in tribological properties of in situ/ex situ composites are attributed to the formation of the glaze layer composed of MoO₃, TiO₂, Al₂TiO₅, NiAl₂O₄, and NiO on the worn surfaces and the difference of the distribution of the ceramics in the matrix.