Tribological behavior of FeCrAl coating sliding against Al2O3 and GCr15 balls from 25 to 400 °C

Abstract Objectives The microstructures, mechanical and tribological properties of the atmospheric plasma sprayed FeCrAl coating are systematically investigated for use as coating material when sliding against Al2O3 and GCr15 balls from 25 to 400 °C. Methods The FeCrAl coating is fabricated by the atmospheric plasma spraying technology. TEM is employed to resolve the fine-scale features of the wear debris collected from the worn surface. Comprehensive microstructural analyses, mechanical properties, and tribological testing were conducted to establish the correlation between coupled materials, temperature and tribological behavior. Results and conclusion The results reveal that the FeCrAl coating with a Vickers micro-hardness of about 300 HV exhibits good impact resistance. When sliding with Al2O3 ball, the material transfer is alleviated considerably due to formation of the smooth worn surface consisting of Fe2O3 and Cr2O3, resulting in low specific wear rate (WRs) of the FeCrAl coating at 400 °C. In the case of GCr15 ball, the change of tribological behaviors can be attributed to the softening of the coupled GCr15 ball with the increased temperature, resulting in wear deterioration at 400 °C. In all cases, the oxide wear debris collected from worn surfaces exhibits consistent microstructural characteristics, consisting of a flocculent composite of nanocrystalline and a certain amorphous aggregate.