LASER CLADDING OF HOT WORK TOOL STEEL (H13) WITH TIC NANOPARTICLES

Abstract

In this study, titanium carbide nanoparticles (TiC) were coated on the surface of X40CrMoV51 (H13) hot work tool steel by laser coating method. Two stage laser cladding method was employed for coating processes. In the first stage, TiC powders were mixed in the phonelic resin and precoated at 50 µm thickness on the surface of steel substrate under vacuum. In the second stage, laser was directed to the surface and then hard coating layers were obtained on the steel surfaces. A CO2 laser with 2000 W power was operated at continuous-wave mode in the experiments. All laser cladding processes were performed under N2 atmosphere and various laser powers were selected to show the effect of laser power on the quality of coated steel surfaces. The morphology and phase structures were examined by scanning electron microscopy, X-ray spectroscopy and optic microscope, respectively. The hardness of coating layers and bonding strength was defined with micro hardness tests and scratch test. The thickness of the coatings layers were measured in the range of 15-130 µm depending on laser powers. It is seen that crack-free, smooth and homogenous coating layers can be obtained at 237 W laser power. According to the hardness and micro-scratch tests results, hardness was improved significantly, and all coating layers had a good metallurgical strength to the substrate.