Performance and damage mechanism of TiN/ZrN nano-multilayer coatings based on different erosion angles

• Published in: Applied surface science Vol. 513; p. 145457
• Main Authors: Chen, Jiao, Zhang, Zhaolu, Yang, Guanjun, Fang, Zhihao, Yang, Zhufang, Li, Zhe, He, Guangyu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.05.2020
• Subjects: Damage mechanism; Erosion angles; Erosion performance; Sand erosion; TiN/ZrN nano-multilayer coatings; Erosion performance; TiN/ZrN nano-multilayer coatings; Sand erosion; Erosion angles; Damage mechanism
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2020.145457

[Display omitted] •Erosion rate of TiN/ZrN nano-multilayer coatings in proportion to the erosion angle.•Diameter, depth and density of the erosion pit vary directly as erosion angle.•Lateral cracks and tensile stress itself are the erosion mechanism at 15° and 45°.•Longitudinal cracks are the main erosion mechanism at 75° and 90° erosion angles.•The cracks are more probable to appear at high angles (75° and 90°). Nano-multilayer coating is an effective method for improving the sand erosion resistance of a material employed in any industrial field. However, very few studies have addressed this subject of research, especially in the aspects of the multi-angles erosion performance and the corresponding mechanism. In this study, a TiN/ZrN nano-multilayer coating was prepared on the Ti6Al4V substrate by employing physical vapor deposition; the nano-layer thickness of the alternating structure of this coating was less than 200 nm. The mechanical and erosion properties of TiN/ZrN were examined, accompanied by varying the erosion angles from 15° to 90°. The 3D surface topographies of the eroded surface were characterized by using a white-light interfering profilometer. The coating damage was examined by cross-sectioning the samples using the focused ion beam (FIB) method. The experiment shows that the maximum erosion rate occurs at 90°, which is approximately 3.1, 2.8 and 1.2 times larger than 15°, 45°, and 75° erosion angles, respectively. The diameter, depth and density of the erosion pit increases with a rise in the erosion angle. The erosion mechanism of the TiN/ZrN nano-multilayer coatings is governed by lateral cracks and the tensile stress of the coating itself at 15° and 45°; further, it is influenced by the longitudinal cracks at 75° and 90°. Lateral cracks in the erosion damage of coating are primarily Mode Ⅱ cracks. The average crack density in the effective FIB trenches reveals that the cracks are more probable to occur at high angles (75° and 90°); this further explains the results of a higher erosion rate at a high erosion angle.