High-temperature tribological properties of the novel NiCr(MoNb)x-Ag self-lubricating composite films

The representative FCC structured NiCr(MoNb)x-Ag (x = 0, 0.65 and 1.05) composite films were developed in this work, and the microstructure, mechanical, and tribological properties were studied. It is shown that small amounts of nm-sized Ag particles are dispersed in the thin film matrix. With the increase of Mo and Nb content, the hardness of the films is enhanced while the elastic modulus increases first and then decreases. The NiCr (MoNb)1.05-Ag composite film shows the best tribological performance. The average friction coefficients of the NiCr-Ag, NiCr(MoNb)0.65-Ag and NiCr(MoNb)1.05-Ag films from room temperature to 600 degrees C are 0.35-0.46, 0.27-0.4 and 0.26-0.32, respectively. NiCr(MoNb)0.65-Ag and NiCr(MoNb)1.05-Ag films show good lubricity at room temperature to 500 degrees C, and NiCr(MoNb)1.05-Ag film still maintains a low friction coefficient at 600 degrees C. The wear rate increases with temperature and decreases successively with increasing Mo and Nb content. Moreover, the distribution of elements in the films with higher Mo and Nb content is more stable at high temperatures, which contributes to the improvement of wear resistance.

Automated summary

The representative FCC structured NiCr(MoNb)x-Ag (x = 0, 0.65 and 1.05) composite films were developed and studied for their microstructure, mechanical, and tribological properties. It was found that small amounts of nm-sized Ag particles are dispersed in the thin film matrix. The NiCr(MoNb)1.05-Ag composite film showed the best tribological performance with low friction coefficients at high temperatures.