High Temperature Wear Coatings for Improving High Output Military Diesel Engine Performance and Durability

Major benefits in performance, reliability, and sustainment cost have been demonstrated for a decade with a ‘new’ class of piston coatings that by their nature, improve the fit of mating piston to bore surfaces in the race and remanufacturing engine industries. Reliable high output engines are fundamentally limited by thermal and tribological performance of cylinder kit piston-ring-bore materials. Additive Abradable Graphite Coatings (AAGC’s) improve fit between component surfaces, cut peak contact stress, create uniform oil film loading, and enhance local lubrication with macroscopic and microscopic mechanisms. Advanced AAGC coatings that can reduce friction and maintain system safe tribological conditions at high temperatures will extend the reach of Advanced Combat Engines (ACE) and other high power density engines towards efficient, reliable, cost effective operation in military and commercial engine markets. Phase 1 bench testing demonstrated the unique ability of AAGC’s to abrade to the fit of mating surfaces, carry high loads at low friction in mixed-boundary lubrication, and function tribo-mechanically at temperatures over 350F, when most oils vaporize. Phase 2 seeks to compare performance and durability of ‘identical’ firing engines with traditional piston coatings versus new, state of the art, AAGC piston coatings.