PLASMA-SPRAYED COATINGS FOR LUBRICATION OF A TITANIUM ALLOY IN AIR AT 430° C

摘要

Plasma-sprayed coatings of pure silver and of composite materials containing silver were investigated as possible self-lubricating coatings for titanium alloys in air at 430 C. Pure silver provided low friction but was prone to severe plastic deformation and excessive transfer except in coating thicknesses of 0.02 mm or less. Additions of nichrome, calcium fluoride, and glass to silver were all beneficial in reducing plastic deformation and otherwise improving the coatings. The longest coating wear life, low wear of Ti alloy pins in sliding contact with the coatings, and a steady friction coefficient of 0.19 were obtained with a four-component coating of 0.17 mm thickness. The coating composition, in weight percent is 30 nichrome-30 Ag-25 CaF2-15 glass.