Effect of different ZrN addition on microstructure and wear properties of titanium based coatings by laser cladding technique

Abstract

In order to improve the wear resistance of TC11 titanium alloy, a mixture of ZrN (10 wt.%, 20 wt.%, 30 wt.%, and 40 wt.%) and TC11 alloy powders are laser cladded on a forged TC11 substrate. The microstructure and wear property of coatings are systematically analyzed. The results show that the microstructure of sample with 10 wt.% ZrN addition has a very fine α + β two-phase microstructure, powders of ZrN are fully melted with no new phase appearance. By increasing the amount of ZrN to 20 wt.%, new phases of TiN0.3 precipitate with the dendritic morphology in the coating. A further increase in ZrN to 30 wt.% and 40 wt.% do not significantly change the microstructure of the cladded layer but increase the microhardness significantly, phases of TiN form with further enhancement of coating hardness. At the bottom of the cladded layer, the morphology of TiN0.3 and TiN precipitations changes into a spherical shape with small size. However, the wear performance of the coatings gradually reduces due to the increase of brittleness, and the superior wear properties of the coating are achieved when sample consisted of 20 wt.% ZrN.