Ni含量对CrNiN涂层结构与性能的影响

Influence of the Ni Content on Structure and Properties of CrNiN Coatings

目的研究Ni元素在CrNiN涂层中的存在形式,阐明Ni含量对CrNiN涂层的微观结构、力学性能和耐腐蚀性能的影响。方法采用磁控溅射技术,在控制Cr靶功率不变的条件下,通过改变NiCr靶电流制备3种不同Ni含量的CrNiN涂层。利用X射线衍射仪(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、聚焦离子束显微镜(FIB)、透射电子显微镜(TEM)、纳米压痕仪、电化学工作站等测试方法表征涂层的成分、组织结构、力学性能和耐腐蚀性能。结果当NiCr靶电流由0.5 A增加到1.0 A时,CrNiN涂层中的Ni含量(均用原子数分数表示)由6.84%增加到13.36%,CrNiN涂层具有明显的(200)择优取向。CrNiN涂层主要由CrN相组成,存在少量的Cr2N相和Ni金属相。随着Ni含量的增加,CrNiN涂层的硬度先增大后减小,当Ni含量为8.57%时,CrNiN涂层的硬度相对于CrN涂层提高了36%,达到了(16.9±0.7)GPa,韧性和抗塑性变形能力也明显提高;CrNiN涂层的腐蚀电流密度逐渐减小,耐腐蚀性增强。当Ni含量为13.63%时,涂层的自腐蚀电位为−0.096 V,腐蚀电流密度为5.21×10^(−9) A/cm^(2),耐腐蚀性能最优。结论随着CrNiN中Ni含量的增多,涂层的致密性提高。当涂层中的Ni含量为8%左右时,其力学性能和耐腐蚀性能均得到提升。

The work aims to study the existing forms of Ni in CrNiN coating were studied,and the effects of Ni content on the microstructure,mechanical properties and corrosion resistance of CrNiN coating were clarified.Three kinds of CrNiN coatings with different Ni contents were fabricated by changing the sputter current of NiCr target and keeping constant power of the Cr target using magnetron sputtering technology.The composition,microstructure,mechanical properties and corrosion resistance of the coating are tested and characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM),focused ion beam microscope(FIB),transmission electron microscope(TEM),nano indentation instrument and electrochemical workstation,respectively.With the increase of NiCr target current from 0.5 A to 1.0 A,the Ni content in CrNiN coating increases from 6.84at.%to 13.36at.%,and the CrNiN coatings has an obvious(200)preferred orientation.The CrNiN coatings are mainly composed of CrN phase,with a small amount of Cr2N phase and Ni metal phase.With the increase of Ni content,the hardness of CrNiN coatings first increases and then decreases.When the Ni content is 8.57at.%,the hardness of CrNiN coatings reaches(16.9±0.7)GPa,which is 36%higher than that of CrN coating,and the toughness and plastic deformation resistance are also improved.The corrosion current density of CrNiN coatings decreases and the corrosion resistance increases.When the Ni content is 13.63at.%,the corrosion potential of the coating is−0.096 V and the corrosion current density is 5.21×10^(−9) A/cm^(2),with the best corrosion resistance.With the increase of Ni content,the compactness of the CrNiN coatings is improved.When the Ni content is about 8at.%,its mechanical properties and corrosion resistance are improved.