同步脉冲偏压对Hi PIMS技术低温沉积CrN涂层结构及性能影响

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

针对高性能CrN涂层无法实现低温可控制备的技术瓶颈,利用具备高溅射材料离化率的高功率脉冲磁控溅射技术,调控同步脉冲偏压,改善涂层生长动力学条件,实现CrN涂层的低温可控沉积。开展同步脉冲偏压与涂层化学组成、组织结构、力学、摩擦学及耐腐蚀性能间关联关系研究。同步脉冲偏压在提升沉积离子束流迁移能的同时可显著降低荷能Ar+对成膜表面的持续轰击作用,达到改善涂层致密性及膜基结合力的目的。此外,沉积CrN涂层晶粒细化显著,硬度及弹性模量明显升高,最高可达13.8 GPa、236.7 GPa。涂层力学性能优化及致密性提升显著改善了摩擦学与耐腐蚀性能,涂层磨损率最低可达2.49×10^(-15) m^(3)/(N·m),同时涂层可耐受120 h中性盐雾腐蚀环境考核。为实现高性能CrN涂层的低温可控制备,扩展其在温度敏感基体领域的适用范围提供了新的设计思路与技术支撑。

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 2.49×10^(-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.