Effects of Synchronized Pulsed-bias on Microstructure and Properties of CrN Coatings Prepared by HiPIMS at Low Temperature

For thermal sensitivity substrates modification, it is a crucial bottleneck to deposit the excellent CrN ceramic coatings at low temperature. With regulating the synchronized pulsed-bias and promoting the coatings growth kinetic driving, this paper aims to achieve the tailoring structural preparation of CrN coatings with excellent mechanical and anti-corrosion properties at low temperature by utilizing the high ionization HiPIMS technique. The correlations of the pulsed-bias, chemical composition, microstructure, mechanical properties, tribological and anti-corrosion behaviors are studied. Due to the selective acceleration mechanism of the deposition ions, which can achieve the increase of adatoms migration energy, and coincidently, decrease the energetic bombardment of Ar+ on the coating growth surface, the synchronized pulsed-bias mode showed significant advantages on reducing internal stress as well as improving the adhesion properties. With the increase of bias voltage value, the microstructure of the as-deposited coatings appeared obvious grain refinement. The morphologies evolved from coarse and transgranular columnar structure to denser columnar structure. Accordingly, the hardness and elastic modulus of the CrN coatings as-deposited exhibited an obvious increase tendency with the maximum value of 13.8 GPa and 236.7 GPa, respectively. Meanwhile, duo to the optimal mechanical properties as well as the highest density, the CrN coating as-deposited showed the most excellent wear resistance and anti-corrosion properties with the minimum wear rate of 2.49x10(-15) m(3)/(N.m) as well as the neutral salt spray corrosion test for 120 h. The study propels the tailoring structural preparation of CrN coatings at low temperature and even provides the new ideas as well as technique support for CrN coatings to develop their applications in the thermal sensitivity materials field.