LASER CLADDING OF HOT WORK TOOL STEEL (H13) WITH NANO TIC PARTICLES
In this study, nano titanium carbide particles are coated on the surfaces of X40CrMoV51 (H13) hot work tool steel to improve the tribological properties of steel surface by laser coating method. Nano TiC having average size of 10 nm are used as coating material and two stage laser cladding method was employed for coating processes. In the first stage, nano TiC powder is mixed in the phonelic resin and then precoated at 50 um thickness on the surface of steels under vacuum. After that laser beam melted the surface of steels and hard coating layer obtained. The effect of laser power on the coating layers were examined using a 2000 W CO 2 laser which operated at continuous wave mode. The morphological structures and phase structures were examined by scanning electron microscopy X ray spectroscopy and optic microscope, respectively. The hardness of coating layers and bonding strength to substrate were defined with microhardness tests and scratch test. The thickness of the coatings layers were measured in the range of 15 130 um according to laser powers It is seen that c rack free, smooth and homogenous coating layers can be obtained at 235 W laser power. According to hardness and micro scratch tests results, hardness was improved significantly and all coating layers had a good metallurgical strength to substrate.