Study On Microstructure And Properties Of Vanadium Nitride-based Composite Films And VN/WN Multilayers

Vanadium nitride films（,V,W）N，（V,W,Al）N composite films and VN/WN multilayerswere prepared by the JGP-450high vacuum multi-target magnetron sputtering technique.The microstructure,cross-section,surface morphology,mechanical,friction properties andoxidation resistance properties were investigated by X-ray diffraction（XRD）,scanningelectron microcopy（SEM）,nano-indentation CSM,high-temperature ball-on-disctribo-meteranalysis,annealing oven and thermo-gravimetry（TG）.The main conclusions in this work are summarized as follows:Vanadium nitride films have a phase structure taking of a （111） preferentialorientation,while vanadium nitride films has a great influence as the N₂flowchanges.Deposition rate of vanadium nitride films decrease gradually with the increase ofN₂flow.The microhardness and elastic modulus of the vanadium nitride films becomebigger firstly and then become smaller and reach a maximum value of22.4GPa and308.8GPa when N₂flow is7sccm,respectively.At room temperature,the friction coefficientof the vanadium nitride films decrease gradually with the increasing of N₂flow and thefriction coefficient reach a minimum value of0.3924when N₂flow is10sccm.The frictioncoefficient of vanadium nitride films decrease to a minimum value of0.2947at650℃when N₂flow is7sccm,then increase.（V,W）N composite films have a face-centered cubic structure VN and h-V2N phase.With the W contents increasing, the relative intensity of peak increases gradually, themicrohardness of the （V,W）N composite films become bigger firstly and then smaller, whilethe friction coefficient is contray, the microhardness of the （V,W）N composite films reach amaximum value of25.1GPa and the friction coefficient reach a minimum value of0.3238when the W content is26.67at.%.（V,W,Al）N composite films have a face-centered cubic structure VWN, WN phases andh-V2N phase when the Al contents are lower than14.86at.%, while （V,W,Al）N compositefilms have a face-centered cubic structure VWN, WN phases and h-V2N and h-AlN phaseswhen the Al contents are higher than14.86at.%. The （V,W,Al）N composite films reach amaximum value of35.5GPa when Al content is14.86at.%. The anti-oxidant properties of（V,W,Al） N composite films are increased at least200℃with the increasing of Al contents.The preferential orientation of VN/WN multilayer films with different modulationperiods were always （111）, their grain size is between VN and WN.With differentmodulation periods, The hardness value of VN/WN multilayer films is3.4GPa higher than that of the hybrid algorithms. As the modulation periods increased, the friction coefficientsof VN/WN multilayer films at RT decreased gradually. The friction coefficient reach aminimum value of0.3069when the modulation period is6nm.