Hard nanocomposite coatings: Thermal stability, oxidation resistance and toughness

The article reports on the enhanced hardness of nanocomposite coatings, their thermal stability, protection of the substrate against oxidation at temperatures above 1000 °C, X-ray amorphous coatings thermally stable above 1000 °C and new advanced hard nanocomposite coatings with enhanced toughness which exhibit (i) low values of the effective Youngʹs modulus E⁎ satisfying the condition H/E⁎ > 0.1, (ii) high elastic recovery We ≥ 60%, (iii) strongly improved tribological properties, and (iv) enhanced resistance to cracking; here E⁎ = E(1−ν2), E is the Youngʹs modulus and ν is the Poisonʹs ratio. At the end trends of next development of hard nanocomposite coatings are briefly outlined.