Microstructure and friction properties of plasma sprayed Al–Si alloyed cast iron coatings

Cast iron coatings were plasma sprayed on aluminum alloy substrate to improve its anti-wear properties. The starting cast iron powders have different contents of alloying elements such as Al and Si, which act as strong graphitizers. The friction and anti-wear performance of the different sprayed cast iron coatings were examined. The results indicated that sprayed cast iron coatings of high Al and Si elements show good friction and wear resistance mainly due to the formation of graphite in the coating. Moreover, the amount of graphitized carbon increases in cast iron coatings with an increase in alloying elements of Al and Si.