Alternative to chrome: HVOF cermet coatings for high horse power diesel engines

High velocity oxygen fuel sprayed face coatings have shown great promise for piston rings used for high power density diesel engines. Various coatings have been tested on both wear test rigs and in an engine. A highly dense HVOF cermet coating was developed with reasonable crack resistance during service. The HVOF coated piston rings wort three to six times lower than chrome plating. Cylinder liner (counter fate) wear was found to be one to three times higher than chrome. The HVOF coating is considered to be an excellent replacement for chrome plating. The coating process is more environmentally friendly than the chrome plating process. Also, the coating has potentially lower or equivalent production cost when compared to chrome.