Use of laser cladding for the synthesis of coatings from high-entropy alloys reinforced with ceramic particles

Abstract

The purpose of this work was to develop methods for obtaining composite coatings based on high-entropy alloys by laser cladding from mixtures of low-entropy powders. Powders of pure copper (Cu), titanium carbide (TiC), aluminum oxide (Al2O3), as well as commercial powders of low- and medium-entropy alloys were used for the implementation of laser additive technologies. The powder particle size ranged from 40 to 150 µm. Coatings were obtained using an ytterbium fiber-optic laser on a steel substrate. The structure of experimental samples was studied on a scanning electron microscope. In order to confirm the composition of the zones found in the studied samples (for chemical and structural analysis of phases in the studied samples), X-ray spectral microanalysis was performed using an energy-dispersive X-ray spectrometer. The phase structure of the obtained samples was studied by X-ray phase analysis using a powder diffractometer using Cu-Kα radiation. The technique used made it possible to obtain composite coatings with inclusions of Al2O3 and TiC. The results of the work open the way to the development of technologies for producing, by laser cladding, highly functional coatings from high-entropy alloys strengthened with reinforcing ceramic particles or from composite materials based on high-entropy alloys, using a combination of commercially available powders of low-entropy and medium-entropy alloys.