Sliding wear characteristics of molybdenum containing Stellite 12 coating at elevated temperatures

The addition of 10wt% Mo encouraged a eutectic reaction to form Co6Mo6C complex carbide and Co3Mo intermetallic in addition to Cr23C6 while causing solid solution hardening of the Co-rich dendritic matrix in the microstructure of the PTA deposited Stellite 12 coating. The addition of molybdenum not only imposed a higher hardness but also enhanced wear resistance. Under oxidation dominated wear conditions (500 and 700°C), the addition of molybdenum provided a remarkable increase in wear resistance in comparison to the lower temperatures (RT and 300°C), due to the development of a protective oxide film on the worn surface. •High temperature tribological behavior of PTA deposited Stellite 12 was investigated.•10wt% Mo addition into Stellite 12 increased the wear resistance.•At RT and 300°C plasticity wear dominated mechanism was operative.•At higher temperatures wear progressed by oxidative mechanism.•Formation of CoMoO4 on the worn surface remarkably increased wear resistance.