Effect of WC-17Co content on microstructure and properties of IN718 composites prepared by laser cladding

Abstract

In this paper, WC-17Co/IN718 composites are successfully produced by the coaxial powder feeding laser cladding technology, and the effect of WC-17Co content on the microstructure, wear behavior and electrochemical corrosion performance of Ni-based composites is studied. Results show that with the increase of WC-17Co content, the composite coatings gradually precipitate Fe-Ni solid solution, TiC, WC and Fe3W3C, the unmelted particles on the top and bottom of the coatings are “agglomerated”, the number of micropores is droped, and the grains are refined. When the mass fraction of WC-17Co in the composite coatings is up to 10%, the WC-17Co particles have less effect on the microhardness and electrochemical corrosion resistance of the composite coating, while when the mass fraction of WC-17Co is increased to 30% and 50%, the microhardness of the composite coatings increase by 36.7% and 102.2% respectively, compared to that of the IN718 coating. What’s more, the wear-resisting property is greatly improved, and their wear rate are respectively 0.83 mg•m−1 and 0.28 mg•m−1 (low to 17.2% compared with IN718 coating). As the content of WC-17Co increases, the electrochemical corrosion resistances of the composite coatings gradually decrease.