Wear- and Corrosion-Resistant Boride-Based Coatings Obtained through Thermal Diffusion CVD Processing

Chemical vapor deposition (CVD) boride coatings obtained through thermal diffusion of boron into metallic base of engineering components provide significant improvement of wear and corrosion resistance, integrity and service life of the components in several times. Thermal diffusion process and coating quality are defined by the batch composition providing the boron deposition and diffusion, temperature and time of the process, type of metallic base and its surface quality, and engineering design of the CVD process system. The obtained coatings with thicknesses of 50–250 up to 300–400 µm (depending on the application) are uniform and dense with consistent “saw‐tooth” structures (for carbon steels) through the entire surface of the components with no delamination issues. Wear test studies demonstrated the coatings’ adequate performance defined by high hardness and specific morphology of the coatings. The formation of hard iron boride wear‐ and corrosion‐resistant protective coatings on steels and ferrous alloys through the thermal diffusion process is described. The features of the coating structure and properties are reported. The major application areas of the commercially produced coatings are presented.