Resarch On Microstructure?mechanical And Tribological Properties Of MoN-Ag?MoMgN And NbSiN-Ag Nanocomposite Films

In this paper,a series of Mo₂N-Ag,MoMgN,NbSiN-Ag composite films with different Ag and Mgwere deposited by magnetron sputtering equipment.The micro-structure,mechanical properties and tribological properties were characterized by X-ray diffraction(XRD),scaning electron microscope(SEM),energy dispersive spectrometer(EDS),nano-indentation and ball-on disc tribo-meter.The results of the study were as follows:The research of MoN-Ag composite films with different Ag content showed that MoN-Ag composite films consisted of fcc-Mo₂N and fcc-Ag phases.With the increase of Ag content,the hardness of the MoN-Ag films first increased and then decreased.When the Ag content was 1.61 at.%,the hardness reached a maximum of 26.679 GPa.At room temperature,with the increase of Ag content,the friction coefficient gradually decreased,and the wear rate first decreased and then rised.When the Ag content was 3.90 at.%,the minimum average friction coefficient was 0.378.When the content was 1.61 at.%,the wear rate reached the lowest value,which was 1.632×10^-8 mm³N^-1mm^-1.From room temperature to 600?,the friction coefficient first increased and then decreased.At 600?,the friction coefficient is the minimum,which was 0.2904,and the wear rate increased monotonically.At 600?,the maximum value was 2.773×10^-7 mm³N^-1mm^-1.The phases of Ag,MoO₃ and Ag MoO₄ all had an impact on the tribological properties of the MoN-Ag composite films.The research results of MoMgN composite films with different Mgcontent showed that MoMgN composite films were composed of fcc-(Mo,Mg)N and hcp-(Mo,Mg)N.The hardness and elastic modulus first increased and then decreased with the increase of Mgcontent,and the maximum values are 25.586 GPa and 350.434 GPa respectively.The friction coefficient of MoMgN composite films at room temperature decreased first and then increased with the increase of Mgcontent.When the Mgcontent was 12.91 at.%,the minimum friction coefficient was 0.3677.At room temperature,wear rate of MoMgN composite films showed a monotonous increasing trend with the increase of Mgcontent.In the temperature range from room temperature to 600?,the friction coefficient of MoMgN composite films decreased first and then rised with the increase of temperature.When the temperature was 200?,the friction coefficient reached the minimum,which was 0.3047.The wear rate increased with increasing temperature,and when the temperature was 600?,the maximum value was 1.286×10^-7 mm³N^-1mm^-1.The simulation calculation by Material Studio software showed that the energy of Mgatoms in the MoN composite film was the lowest when replacing Mowith Mg,so it tended to form replacement solid solution.The phases of Mgand MoO₃ had an impact on the tribological properties of the MoMgN composite films.The research results of NbSiN-Ag composite films with different Ag content showed that NbSiN-Ag composite films was composed of fcc-NbN,hcp-NbN and fcc-Ag.With the increase of Ag content,the hardness and elastic modulus of the NbSiN-Ag composite films gradually decreased.At room temperature,with the increase of Ag content,the average friction coefficient of the NbSiN-Ag composite films first increased and then decreased,and the wear rate gradually increased.From room temperature to 600?,the average friction coefficient of the NbSiN-Ag composite films gradually decreased as the temperature rised.The minimum value was obtained at a temperature of 600?,and the value was 0.2705.The wear rate showed a monotonous increasing trend with the increase of temperature.The phases of Ag,Nb₂O₅,Ag₂O,AgNbO₃ effect the tribological properties of the NbSiN-Ag composite films respectively.