Latest Development in Synthesis and Modification of Hard Coatings

The latest progress in synthesis and modification of hard coatings was tentatively reviewed. The discussions, on hot-spot subjects with specific examples, highlighted on:i) novel techniques to synthesize hard coatings at high deposition rate, low temperature and pressure, including but not limited to high power impulse magnetron sputtering, physical vapor deposition, filtered cathodic arc deposition and magnetron sputtering; ii) design of microstructures, growth of amorphous/nano-structured composite coatings, such as nc-TiN/a-Si₃N₄/nc-TiSi₂ coatings, properties modification by removal or doping of oxygen; and iii) exploration in deposition of advanced hard coatings, including films with high tenacity and strong crack extension resistance, films with high thermal stability and strong oxidation resistance, and films of metal boride with super-hardness and self-lubrication capability. Moreover, the development trends, existing problems, possible solutions and mechanisms, were also briefly discussed in a though provoking way.