Influence of lubricious oxides formation on the tribological behavior of Mo-V-Cu-N coatings deposited by HIPIMS

Abstract

The variations of microstructure, mechanical properties, and oxidation behavior of Mo-V-Cu-N coatings are directly correlated to the chemical compositions, which significantly affects their tribological behavior. The aim of this work was to characterize Mo-V-Cu-N coatings with different chemical compositions deposited by high power impulse magnetron sputtering (HIPIMS) using single Mo-V-Cu segmental target, and to investigate the correlations between the lubricative oxides formed on coating surfaces with the variation of tribological behavior at different temperatures. The oxidation of Mo-V-Cu-N coatings started at 400 °C with the lubrication oxides of MoO and Cu-MoO were formed, which led to the decrease in coefficients of friction and wear rates of the coatings. It was found that the rapid outward diffusion of Mo and Cu atoms took place preferentially at around the growth defects (e.g. microparticles and pores). The incorporation of V atoms into Mo-Cu-N coatings enhanced the oxidation resistance at temperatures below 400 °C. At 500 °C, all the fcc B1-MoN and VN phases disappeared due to the severe oxidation, and the V 2 O 5 phase was first appeared. Even though a relatively low coefficient of friction was obtained at 500 °C, the wear resistance of Mo-V-Cu-N coatings was decreased due to the severe oxidation and loss of mechanical strength.

Effect of Cu doping on the microstructure and mechanical properties of AlTiVN-Cu nanocomposite coatings

“…As shown in Fig. 1, four different vertical substrate distances (D = 4, 10, 16, 22 cm) were designed to prepare AlTiVN-Cu coatings with various compositions, especially for the addition of V and Cu, similar to our previous studies for the design of Mo-V-Cu-N coatings [28]. Before deposition, all the samples were treated ultrasonically in anhydrous ethanol and then fixed on the different vertical position holders in the chamber after dried in air.…”

A New insight into friction transfer behavior of MoCN coatings: the tribo-activated formation of carbonitride based nano-twisted helix wear debris

“…3 (c, f and i), the C 1s spectra of MoCN coating can be deconvolved into four peak positions at 283.4, 284.8, 286 and 287.5 eV. These four peak positions are corresponding to C-Mo, sp 2 C = C, sp 3 C-C and C-N, respectively (Fig. 3c) [29] .…”

“…Transition metal nitrides deposited by sputtering method are characterized by good tribological and mechanical properties that have been widely used in various advanced engineering industry [1][2][3] . As a typical transition metal nitride, molybdenum nitride (MoN) exhibits high hardness, low friction coe cient at high temperature and high wear resistance, which has been proved to have great potential application for wide range of tribological elds.…”

Effect of V/Mo Atomic Ratio on the Microstructure and Mechanical Properties of MoVCuN Coatings

“…As a promising self-lubricating coating, Mo-Cu-N coatings have received extensive research in recent years [ 1 , 2 , 3 , 4 ]. Because of the formation of lubricating oxides of MoO 3 and CuMoO 4 (MoO 3 + CuO→CuMoO 4 ), Mo-Cu-N coatings demonstrated exceptional tribological properties, including a low coefficient of friction and high resistance to wear, particularly at room temperature [ 5 , 6 , 7 ]. However, the wear rate of the Mo-N coatings was comparatively high at 500 °C as a result of severe oxidation at high temperatures; this restricted the application of self-lubricating coatings at high temperatures [ 8 , 9 ].…”