等离子喷涂NiAl-V_(2)O_(5)/CuO复合涂层的宽温域摩擦学行为

Tribological Behaviors of Plasma Sprayed NiAl-V_(2)O_(5)/CuO Composite Coatings at Wide Temperature Range

目的以具有较好低温润滑性能的V_(2)O_(5)和CuO为复合润滑相,设计并制备在宽温域下具有良好摩擦学性能的NiAl基高温润滑耐磨涂层。方法采用大气等离子喷涂技术(APS)制备了不同配比的NiAl-V_(2)O_(5)/CuO复合涂层,并探究其在宽温域内(RT~800℃)的摩擦学性能。利用SEM(扫描电子显微镜)、XRD(X射线衍射仪)和Raman(激光拉曼散射仪)等,分析了涂层在宽温域下的摩擦表面结构和物相变化及磨损机理。结果复合涂层为典型的等离子喷涂层状结构,氧化物分布较为均匀,随氧化物含量的增加,涂层孔隙率上升。复合涂层在宽温域内有良好的润滑性能,室温和高温(800℃)下NiAl-10%V_(2)O_(5)/CuO涂层的摩擦因数分别低至0.39和0.21。磨损率随复合氧化物含量的增加而增大,但在室温和高温段均较低,其中10%V_(2)O_(5)/CuO添加的复合涂层在室温和高温下的磨损率分别为4.3×10^(‒5) mm^(3)/(N·m)和5.1×10^(‒5) mm^(3)/(N·m)。高温摩擦促使三元氧化物Ni_(3)V_(2)O_(8)、Cu_(3)V_(2)O_(8)和CuV_(2)O_(6)的生成,这些新生相与CuO、V_(2)O_(5)、NiO等在磨损表面形成润滑层。结论V_(2)O_(5)/CuO的复配明显改善了涂层在室温和高温段的摩擦学性能,但随着氧化物含量的增加,涂层力学性能下降,磨损率随之增大。高温下涂层润滑性能的明显提升归因于磨损表面形成的三元氧化物高温润滑膜。

This work aims to design and prepare NiAl based high temperature lubricating and wear-resistant coatings with good tribological properties in a wide temperature range using V_(2)O_(5) and CuO as composite lubricating phases.The composite coatings with different mass ratios are fabricated by atmospheric plasma spraying technology(APS),and investigated tribological properties in a wide temperature range(RT~800℃);used SEM(scanning electron microscope),XRD(X-ray diffraction)and Raman(laser Raman scattering)to analyze the friction surface structure,phase change and wear mechanism of the coating in a wide temperature range.The composite coating is a typical plasma sprayed layered structure,and the oxide distribution is relatively uniform.With the increase of oxide content,the porosity of the coating increases;The composite coating has good lubrication performance in a wide temperature range.The friction coefficients of NiAl-10wt.%V_(2)O_(5)/CuO coating at room temperature and high temperature(800℃)are as low as 0.39 and 0.21 respectively.The wear rate increases with the increase of composite oxide content,but it is low at room temperature and high temperature.The wear rate of composite coating added with 10wt.%V_(2)O_(5)/CuO is 4.3×10^(‒5) mm^(3)/(N·m)and 5.1×10^(‒5) mm^(3)/(N·m)at room temperature and high temperature respectively.High temperature friction promotes the formation of ternary oxides Ni_(3)V_(2)O_(8),Cu_(3)V_(2)O_(8) and CuV_(2)O_(6).These new phases form a lubricating layer on the wear surface with Cuo,V_(2)O_(5) and NiO.The combination of V_(2)O_(5)/CuO significantly improved the tribological properties of the coating at room temperature and high temperature,but with the increase of oxide content,the mechanical properties of the coating decreased and the wear rate increased.The obvious improvement of the lubricating performance of the coating at high temperature is attributed to the ternary oxide high temperature lubricating film formed on the wear surface.