Effect Of Ag On Microstructure And Properties Of Nitride Films

Using a multi-target reactive magnetron sputtering technique,films with different Ag contents were prepared on 304 stainless steel and silicon.The X-ray diffraction(XRD),nanometer integrated test system,high temperature friction and wear tester,and scanning electron microscope were used.(SEM)and its energy spectrometers,electron transmission microscopy(TEM)and other instruments and equipment were used to characterize the microscopic phase structure,mechanical properties,and friction and wear properties of the composite films prepared at the various temperatures.The effects of soft metal Ag on the microstructure,friction properties and mechanical properties of WNbN composite film,NbN composite film and VCN-Ag composite film were studied.The results are as follows:WNbN-Ag composite film consists of hexagonal WNbN,face centered cubic WNbN,hexagonal NbN,single phase Nb,and Ag five-phase structure.The hardness and elastic modulus of WNbN-Ag composite film gradually decreased.At room temperature,the WNbN-Ag composite film exhibited an increasing and then decreasing friction coefficient as with Ag content in the WNbN-Ag composite film.Increasing gradually;at temperatures between 300°C and 700°C,the friction coefficient of the WNbN-Ag composite film shows a decreasing trend as the ambient temperature continues to increase.The wear rate gradually increases with the Ag content.Increase;Addition of Ag makes WNbN film in the high temperature range significantly reduce the friction coefficient,the wear rate also decreased slightly,played a good role in friction reduction and lubrication.NbN-Ag composite film consists of face-centered cubic NbN and densely packed hexagonal NbN dual-phase structure.The Ag content has no effect on the phase composition in the film,but it has a certain influence on the preferred orientation of the film.The NbN film has a hardness of 25.2 GPa and a modulus of elasticity of 327.1 GPa.With the increase of Ag conten.When Ag content was 5.36 at.%,the maximum value was 29.1GPa.The elastic modulus of NbN-Ag composite film gradually decreased with the increase of Ag content.what the NbN-Ag composite film decreases gradually with the increase of Ag content.When the Ag content reaches 19.01 at.%,the average friction coefficient reaches a minimum value of 0.38.The wear rate of NbN-Ag composite film first decreases and then increases with the increase of Ag content.When the temperature rises from room temperature to 600°C,the friction coefficient of the NbN-Ag composite film is lower than that of the NbN film.The friction coefficient of the NbN-Ag composite film first increases and then decreases.The wear rates of NbN-Ag composite film was lower than that of NbNfilm,and both wear rates increased with the increase of temperature.It can be seen that improves the film at high temperatures to a certain extent.VCN-Ag composite membrane is composed of tetragonal and face-centered cubic dual-phase structure.When the Ag content is lower than 1.24 at.%,the film is grown in the preferential orientation of VN(111).When Ag content increases,the Ag content increases.After increasing to 7.34 at%,the film was grown in the preferential orientation of VN(220).With the increase of Ag content,the intensity of VN(111)diffraction peak gradually weakened.When the Ag content increased to 14.75 at%,the diffraction peak almost disappeared.This is due to the grain refinement due to the addition of Ag.With the increase of Ag content,the hardness of VCN-Ag composite film gradually decreased.The VCN film has a hardness of 28.2 GPa and a modulus of elasticity of 321.9 GPa.When the Ag content was 14.75 at%,respectively.Ag addition did not improve the friction and wear properties of the film at room temperature.When the friction temperature is 300~500°C,the friction coefficient of VCN film and VCN-Ag composite film increases first and then decreases with the increase of temperature,and the friction coefficient of VCN-Ag composite film is obviously lower than that of VCN film.The wear rate of VCN film and VCN-Ag composite film increased with increasing temperature,and the wear rate of VCN-Ag composite film was significantly lower than that of VCN film.The oxidation phase generated during friction is the main cause of changes in the friction coefficient and wear rate.