WC-Co cermet coatings were fabricated by using Warm Spraying, which is a modification of HVOF spraying to lower the temperature of the propellant gas below the melting point of Co. By changing the processing parameters, specimens were prepared for hardness, abrasion wear and particle erosion tests. Their microstructures were examined by SEM and XRD. The microstructure clearly showed the effects of suppression of the dissolution of WC into the Co phase, which is the major cause of embrittlement of the conventional HVOF sprayed WC-Co coatings. By combinations of adequate feedstock powder and processing parameters, it was possible to take advantage of fine WC grain size to prepare coatings with higher hardness (HV ＞ 1400), smoother surface (Ra ＜ 2 μm), and moderately improved wear performances compared with conventional HVOF coatings.
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