Tribological properties of Ni-Cr-W Matrix High Temperature Self-lubrication Composites Sintered by Hot Isostatic Pressing

The high temperature self-lubrication Ni-Cr-W matrix composites were prepared by powder metallurgy and sintered by hot isostatic pressing (HIP). Atomized Ni-Cr-W powder was mixed with friction components of MoS2 and Graphite. The mixed powders were cold pressed 450MPa and sintered at 1100 degrees C similar to 1200 degrees C in the presence of argon atmosphere for 1 hour under 180MPa hot isostatic pressing with respect to their application in slide bearing bushing. The tribological properties are investigated on UMT-2 tester in ball-on-disc against alloy steel ball. The results showed that the appropriate addition of MoS2 show excellent antifriction and wear resistance. And the friction coefficients and wear rates decrease over the wide temperature range of 25 degrees C similar to 600 degrees C compared that of the composites by pressureless sintered method. The results indicated that HIP technology had an obviously strengthening effect on the density, and anti-press strength.