High temperature/low speed sliding wear behavior of Ni-Cr-W matrix composites against IC10 pin.

Ni-Cr-W matrix cermet composites were prepared using powder metallurgical technology, and their microstructures, phase compositions, and mechanical properties were determined. Specifically, the tribological performances of the Ni-Cr-W composites were evaluated at a speed of 0.5 mm/s from room temperature to 800 °C, and their friction-reducing mechanism was clarified. The results showed that the NiCrW/Al 2 O 3 /Ag composite had the highest mechanical strength, with a 94.5 % increase in tensile strength compared to NiCrW/Al 2 O 3. The NiCrW/Al 2 O 3 /SrCO 3 composite exhibited the best high-temperature tribological performance because the chemical reaction on the friction surface generated new lubricating phases consisting of NiO, WO 2 , WO 3 , and Sr 2 CrO 4. These acted synergistically lubricate and anti-wear with the Al 2 O 3 , Cr 2 O 3 , and NiCr 2 O 4 , and formed a continuous glaze layer on the wear surface. Furthermore, the multiple roles of nano-alumina in the obtained composite and its service in friction were discussed. [ABSTRACT FROM AUTHOR]