Cr基过渡层对CrWN涂层摩擦学性能的影响
Effects of Cr-Based Interlayers on Tribological Properties of CrWN Coatings
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摘要: 本文探究了Cr过渡层及Cr-CrN过渡层对CrWN涂层耐磨性能的影响,制备具有良好的减磨耐磨性能的CrWN涂层。采用等离子增强磁控溅射工艺,在碳化钨基体表面制备CrWN涂层,Cr-CrWN涂层、Cr-CrN-CrWN涂层。通过扫描电子显微镜,X射线光电子能谱仪,X射线衍射仪,纳米压痕仪,洛氏硬度计和摩擦磨损实验机对涂层表面形貌、力学性能及摩擦磨损性能进行表征及分析。三种CrWN涂层均以面心立方结构的CrN相和W2N相构成。Cr-CrN-CrWN涂层的膜基结合强度最高,为HF1等级。CrWN涂层的硬度为21.5 GPa,引入Cr过渡层及Cr-CrN过渡层均未对涂层硬度及弹性模量造成显著影响。但通过摩擦磨损实验结果表明Cr过渡层及Cr-CrN过渡层均可降低涂层的摩擦系数并提高涂层的耐磨损性能,在稳定摩擦阶段CrCrWN涂层和Cr-CrN-CrWN涂层的摩擦系数分别为0.656,0.703,磨损率分别为1.366×10-6mm3/(N·m)、1.247×10-6mm3/(N·m);且磨损后磨痕表面无犁沟及裂纹,涂层未出现明显剥落。因此,Cr过渡层及Cr-CrN梯度过渡层可改善CrWN涂层的摩擦学性能及结合强度,并提高涂层的耐磨损性能。Abstract: This work investigates the effects of Cr and Cr-CrN transition layer on the wear resistance of CrWN coating and prepares CrWN coating with excellent wear resistance. CrWN coating,Cr-CrWN coating and Cr-CrNCrWN coating are deposited on tungsten carbide substrates using plasma enhanced magnetron sputtering. The surface morphology,mechanical and tribological properties of the coating are analyzed by scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),Nano-indentation,Rockwell hardness tester and friction tester. The coatings are composed of face-centered cubic CrN and W2 N phases. Cr-CrNCrWN coating has the highest adhesion strength of coating substrate,which is HF1 grade. The hardness of CrWN coating is 21.5 GPa. The introduction of Cr transition layer and Cr-CrN transition layer did not significantly affect the hardness and elastic modulus of the coating. However,Cr transition layer and Cr-CrN transition layer can reduce the friction coefficient and improve the wear resistance of the coating. The friction coefficient of the coatings is 0.656 and 0.703,and the wear rate is 1.366×10-6 mm3/(N·m)and 1.247×10-6 mm3/(N·m) respectively in stable friction stage. Moreover,no furrows and cracks on the surface and no obvious spalling of the coating are found after wear. Therefore,the introduction of Cr transition layer and Cr-CrN transition layer can improve the adhesion of the coating/substrate and the wear resistance of the coating.