DEVELOPMENT OF MoS2- CONTAINING Ni-Cr BASED ALLOYS AND THEIR HIGH-TEMPERATURE TRIBOLOGICAL PROPERTIES
(1.College of Mechanical Electronic Engineering,China University of Mining and Technology, Xuzhou 221008, P. R. China;
2.State Key Lab for Powder Metallurgy, Central South University of Technology, Changsha 410083, P. R. China)
2.State Key Lab for Powder Metallurgy, Central South University of Technology, Changsha 410083, P. R. China)
Abstract: B-and MoS2-containing Ni-Cr based self-lubricating materials were prepared by P/M hotpressing the mixture of alloyed Ni-Cr powder, elemental Mo and B powders and MoS2 powder. The phase constituents were analysed using an X-ray diffractometer, and the hardness was measured using a Brinell’s machine. The friction coefficients and wear rates of the studied materials were determined by means of pin-on-disc tribometer. The results showed that the studied materials are mainly composed of Ni-based solid solution, Cr3S4 and MoB; the wear debris are mainly composed of NiO, CrO,xNiO·MoO3·yH2O, Cr2O3 and nickel-based solid solution at 700℃; the Ni-Cr-Mo-B-4MoS2 alloy has the best tribological properties, over a wide range of temperature from 20℃to 700℃, its friction coefficient is 0.14~0.26 and its wear rate is 1.6×10-14~1.2×10-13m3/N·m.
Key words: Ni-Cr based alloy self-lubricating tribological properties high-temperature