The development of homogeneous, dense, and smooth hard coatings is a challenging task, and that is why the high power impulse magnetron sputtering (HiPIMS) method has been proposed to tailor and control the microstructure through the modification of the duty cycle. HiPIMS offers extensive possibilities to obtain good quality films with fine and dense morphology. In this work, the synthesis of Cr_xN coatings by HiPIMS with the variation of duty cycle (τ = 2.7% and 12%), substrate bias voltages (V_b = −150 and − 250 V), and gas ratio (f_N2/Ar = 0.2 and 0.4) was evaluated. The influence of these processing conditions on the chemical composition, microstructure, and adhesion of HiPIMS Cr_xN was investigated. A significant increment of the deposition rate and the chromium content in the Cr_xN coatings is observed at τ = 12%; meanwhile, at τ = 2.7%, films showed high nitrogen content. The crystalline phases like α-Cr + h-Cr₂N, h-Cr₂N, and h-Cr₂N + c-CrN were identified in the as-deposited films. The Cr-rich coatings presented faceted columns with cauliflower-like surface morphology, while the growth of the h-Cr₂N phase caused a grain size refinement and a denser microstructure. The surface morphology of the h-Cr₂N coatings changed from pyramidal to stacked pyramids with the reduction of the duty cycle. The transformation of the h-Cr₂N to c-CrN leads to highly dense columnar microstructures with a fine granular morphology and a smooth surface. The duty cycle strategies can be applied to develop a particular microstructure with specific chemical composition and crystallographic phases, resulting in an alternative method to produce graded or multilayer systems. The duty cycle reduction increases the interfacial adhesion strength of the coatings.

开发均匀、致密和光滑的硬涂层是一项具有挑战性的任务，这就是为什么提出了高功率脉冲磁控溅射 (HiPIMS) 方法来通过修改占空比来定制和控制微观结构的原因。HiPIMS 提供了获得具有精细和致密形态的优质薄膜的广泛可能性。在这项工作中，通过 HiPIMS合成 Cr _x N 涂层，其中占空比（τ = 2.7% 和 12%）、衬底偏置电压（V _b  = -150 和 - 250 V）和气体比（f _{N 2/ Ar} = 0.2 和 0.4) 进行了评估。这些加工条件对 HiPIMS Cr _x的化学成分、微观结构和附着力的影响N进行了调查。在 τ = 12% 时观察到沉积速率和 Cr _x N 涂层中铬含量的显着增加；同时，在 τ = 2.7% 时，薄膜显示出高氮含量。在沉积膜中鉴定出结晶相，如 α-Cr + h-Cr ₂ N、h-Cr ₂ N 和 h-Cr ₂ N + c-CrN。富铬涂层呈现出具有菜花状表面形态的多面柱，而 h-Cr ₂ N 相的生长导致晶粒尺寸细化和更致密的微观结构。随着占空比的降低，h-Cr ₂ N 涂层的表面形貌从金字塔形变为堆叠金字塔形。h-Cr ₂的转化N 到 c-CrN 导致具有细颗粒形态和光滑表面的高密度柱状微观结构。占空比策略可用于开发具有特定化学成分和结晶相的特定微观结构，从而产生生产渐变或多层系统的替代方法。占空比的降低增加了涂层的界面粘合强度。