Effects of post-heat treatment on microstructure and properties of laser cladded composite coatings on titanium alloy substrate

摘要: Abstract The composite coatings were produced on the Ti6Al4V alloy substrate by laser cladding. Subsequently, heated at 500 °C for 1 h and 2 h then cooled in air. Effects of post-heat treatment microstructure, microhardness fracture toughness investigated scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), optical (OM). Wear resistance was evaluated under dry sliding reciprocating friction condition room temperature. results indicated that mainly consist a certain amount coarse white equiaxed WC particles surrounded white-bright W 2 C, great deal fine dark spherical TiC matrix composed α (Ti), Ti Ni TiNi phases. phase constituents microstructure almost negligible due to low However, could decrease residual stress increase coatings, improved from 2.77 MPa m 1/2 3.80 MPa m 4.43 MPa m with heat 2 h, respectively. mutual role would contribute reduction cracking susceptibility. Accompanied toughness, reduced slightly. dominant wear mechanism all abrasive wear, characterized micro-cutting or micro-plowing. significantly average coefficient reduce fluctuation change time. appropriate time (approximately 1 h) had minimal effect mass loss volume loss. Moreover, improvement will also be beneficial long service.