PLASMA-SPRAYED TiN COATING HAVING EXCELLENT HARDNESS AND TOUGHNESS, THE PREPARATION METHOD THEREFOR, AND A MOLD COATED WITH SAID TiN COATING

摘要

Disclosed is an agglomerated TiN powder, the powder comprising spherical aggregates having particle diameters of 40 to 80 μm and formed by the agglomeration of Ti and N having the atomic fractions of 72% and 28% respectively. Also provided is a TiN coating obtained using the powder. The three-strong-peak phase of the coating is a TiN phase, and also has partial TiO, TiO₂, and Ti₃O oxide phases; the coating has layered distribution of bright and dark phases, and the joint between the interior of the layered structure and the layer structure is provided with a small number of pores; the joint between the coating and a base has no microscopic defects such as cracks and is well jointed. The supersonic plasma-sprayed TiN coating achieves hardness as high as 1210HV_0.1, thereby enhancing the wear resistance of the coating. The coating has good fracture toughness, thereby enhancing the fracture mechanical performance inside of the coating and extending the fatigue life of the coating. Also provided are a preparation method for the TiN coating, and a mold coated with said TiN coating.