In this work, the influence of the type of binder (cobalt and iron aluminide intermetallic) on microstructure, mechanical properties and wear resistance of high velocity oxy-fuel (HVOF) sprayed tungsten carbide-based hardmetal coating was studied. Intermetallic binder, with different amount of boron 0, 0.05 and 0.1 weight percent B, were produced using vacuum arc melting and cast chill, prepared under controlled atmosphere using ring grinding, blended with tungsten carbide powder (7 µm) and then sintered and crushed into particles large enough to flow in the spray equipment. The mechanical and wear properties of the intermetallic composite coating compared with the prepared conventional cobalt binder coating WC-30 vol%Co and commercial coating WC-20 vol%Co. The coating characterization included optical microscopy and scanning electron microscopy of metallugraphically prepared cross section, hardness and toughness measurement, phase composition by X-ray diffraction and wear behavior by ball on disk. Based on x-ray diffraction result, the proportion of WC transformed to W 2 C is higher for all of the WC-Co compared with the WC-(FeAl-B) Coating and in WC-Co coating no traces of ?-carbide phases (Co 6 W 6 C, Co 3 W 3 C) were observed. Result showed that the hardness of WC-FeAl Coatings is higher than those WC-Co coatings. The toughness was found to be improved when boron doped with iron aluminide in intermetallic matrix composite coatings. The study of wear tracks indicated that the dominant wear mechanism in both WC-Co and WC-(FeAl-B) coating was carbide pull out and subsurface fracture. The iron aluminide binder doped with 0.05 wt% boron had lower coefficient of friction and weight loss than the other coating even with commercial coating WC-20 vol%Co witch has a lower percentage of binder phase and tungsten carbide particle size (0.7 µm) were competitive. In addition, the friction and wear behavior at elevated temperature and failure mechanism of coatings were investigated. The result indicated that the sliding wear resistance of WC-FeAl-0.05B coating is higher than that of WC-Co coating at high temperature. Subsurface fracture, carbide pull out and WC grain break dominant in both coating but in WC-Co coating followed with extrusion of the supporting binder phase and adhesive wear. WC-(FeAl-B) coating showed an improvement in wear properties at low temperature and significantly at high temperature than WC-Co coating. Keywords Composite coating, Tungsten carbide, Iron alumonide, Thermal spray, HVOF, Wear, Toughness
