Dry sliding wear behavior of cold sprayed aluminum amorphousanocrystalline alloy coatings

摘要

Dry sliding wear behavior of cold sprayed Al amorphousanocrystalline alloy coatings in as-sprayed and heat treated conditions is reported. As-sprayed coatings exhibit higher coefficient of friction (COF) and wear volume loss 68% greater than heat treated coatings. Wear mechanism is elucidated in terms of worn surface and subsurface analysis, splat bonding and tribochemical oxidation layer formation. Themicro-abrasion and splat delamination resulted in higher wear loss in as-sprayed coatings. Heat treated coatings exhibit lower wear rate due to dense and partially crystallized structure which results in plastic deformation assisted wear. The tribo-chemical layer formation during thewear is studied by energy dispersive spectroscopy (EDS) elemental analysis and supported by thermodynamic computation and flash temperature estimation. The fracture behavior of the splats is investigated using tensile testing of free standing coatings in as-sprayed and heat treated conditions and correlated with the wear mechanism.