Ni含量对CrN涂层抗磨蚀性能的影响研究

目的 探究在模拟海洋环境下，Ni的掺入对CrN涂层耐磨性能的影响，研究不同Ni含量的CrNiN涂层的磨蚀行为。方法 采用磁控溅射方法对CrNiN涂层中的Ni含量进行调控，制备CrN涂层、Ni掺杂含量分别为15.85%(原子数分数)和39.06%的CrNiN涂层。通过干摩擦试验和模拟海水磨蚀试验，对3种涂层的力学性能和磨蚀行为进行研究对比，并分析其摩擦损伤机理。结果 在干摩擦试验条件下，CrNiN涂层的摩擦学性能主要由涂层的力学性能决定，Ni原子数分数为15.85%的CrNiN涂层兼具高硬度和良好韧性，磨痕最浅，其磨损率在3种涂层中最低，为9.1×10^–7 mm³/(N.m)，而在模拟海洋磨蚀的开路电位(OCP)下，Ni原子数分数为15.85%的CrNiN涂层的磨损率大于CrN涂层，CrN涂层具有最低的摩擦因数以及最低的磨损率。3种涂层在正电位(+0.6 V)时的磨损率显著大于开路电位(OCP)下的磨损率，说明腐蚀降低了涂层的耐磨性。通过对腐蚀产物进行分析，表明CrN的腐蚀产物主要是CrO2以及Cr2O3，具有一定的润滑作用，而含Ni的CrNiN涂层在腐蚀过程中产生了NiO，对涂层的耐磨性产生了不利影响。结论 在干摩擦试验条件下，CrNiN涂层的摩擦学性能主要由涂层的力学性能决定，Ni原子数分数为15.85%的CrNiN涂层兼具高硬度和良好韧性，从而更耐磨。在模拟海洋磨蚀试验条件下，CrNiN涂层的腐蚀产物严重影响其磨蚀性能。

Effect of Ni Content on Wear Resistance Performance of CrN Coatings

Seawater is a complex corrosive electrolyte solution. Chloride ions can cause severe damage to the oxide film on the metal surface, accelerating the corrosion process of materials. Metals serving in marine environments experience severe coupled corrosion and wear damage. However, these components are prone to corrosion and wear in marine environments, leading to the destruction of the surface''s passive film and severe damage to the metal under the combined action of wear and corrosion. To protect alloys in marine conditions from the erosion of friction, metal nitride coatings have been widely applied to alloy surfaces in recent years. These coatings exhibit significant advantages in improving substrate thermal stability, oxidation resistance, and corrosion resistance. CrN coatings have been widely used in cutting tools and molds due to their excellent mechanical properties, corrosion resistance, and oxidation resistance. However, the low toughness of CrN coatings may lead to catastrophic failure through brittle detachment during frictional processes, severely limiting their application scenarios. Studies have shown that the addition of nickel (Ni) elements to CrN coatings can effectively improve their hardness and toughness. Currently, there are few reports on the tribological performance of CrNiN coatings in simulated seawater environments. The aim of this study was to investigate the influence of nickel addition on the wear resistance of CrN coatings in simulated marine environments and explore the wear behavior of CrNiN coatings with different nickel contents. Magnetron sputtering was used to control the nickel content in CrNiN coatings. CrN coatings with a thickness of 3 μm and different nickel contents, 15.85at.% and 39.06at.%, were prepared on 431 stainless steel substrates. Dry friction experiments and simulated seawater wear tests were conducted to study the mechanical properties and wear behavior of the three kinds of coatings and analyze their frictional damage mechanisms. Under dry friction conditions, the tribological performance of CrNiN coatings was mainly determined by the mechanical properties of the coatings. CrNiN coatings with 15.85at.% nickel content exhibited both high hardness and good toughness, resulting in the shallowest wear track and the lowest wear rate among the three kinds of coatings, with a value of 9.1×10–7 mm3/(N.m). However, under the open circuit potential (OCP) of simulated seawater wear, CrNiN coatings with the best mechanical properties had a higher wear rate than CrN coatings. CrN coatings exhibited the lowest friction coefficient and wear rate. The wear rate of the three kinds of coatings at a positive potential (+0.6 V) was much higher than that at the OCP, indicating that corrosion reduced the wear resistance of the coatings. Analysis of the corrosion products revealed that the main corrosion products of CrN were CrO2 and Cr2O3, which provided some lubrication effect. In contrast, the corrosion process of CrNiN coatings containing nickel produced NiO, which had an adverse effect on the wear resistance of the coatings. In conclusion, under dry friction conditions, the tribological performance of CrNiN coatings is mainly determined by the mechanical properties of the coatings. CrNiN coatings with 15.85at.% nickel content exhibited high hardness and good toughness, resulting in better wear resistance. However, under simulated seawater wear conditions, the corrosion products significantly affect the wear performance of CrNiN coatings, thereby reducing their wear resistance.