An anti-fretting coating composition that is operationally stable at temperatures of 800 F. to 2650 F. is provided. The anti-fretting coating composition primarily includes cobalt and aluminum oxide and may also include other modifying phases that enhance the overall tribological performance. A component coated with the anti-fretting coating composition is also provided. The component includes a substrate having a first contact surface shaped to cooperate with a second contact surface of an abutting member in a manner which can develop wear between the first contact surface and the second contact surface. The first contact surface includes an anti-fretting coating thereon formed from the disclosed anti-fretting coating composition.

Undercooled liquid metallic core-shell particles, whose core is stable against solidification at ambient conditions, i.e. under near ambient temperature and pressure conditions, are used to join or repair metallic non-particulate components. The undercooled-shell particles in the form of nano-size or micro-size particles comprise an undercooled stable liquid metallic core encapsulated inside an outer shell, which can comprise an oxide or other stabilizer shell typically formed in-situ on the undercooled liquid metallic core. The shell is ruptured to release the liquid phase core material to join or repair a component(s).