AlCrNbSiTiN High-Entropy Nitride Hard Coatings

High entropy alloys which are composed of at least five primary elements exhibit better performance than the conventional alloys in terms of high hardness, high toughness and high-temperature resistance, thus showing great potential for application in the field of protective coatings. However, the research on high-entropy alloy coatings is still in its initial stage, and there is a lack of in-depth research on the structure and performance of the coatings. In this chapter, the nanocomposite high entropy alloy nitride coatings based on AlCrNbSiTi system were fabricated using reactive RF magnetron sputtering and arc ion plating techniques. The effects of negative bias voltage applied to the sample on the phase composition, grain size, orientation and microstructures of the coatings were characterized, and the mechanical properties, friction behaviour, and temperature resistance of coatings were investigated systematically. The wear friction behaviour and the elemental diffusion and the oxidation mechanism of the coatings at high temperatures were studied.