| As the typical hard films,Ti-Al-N and W-Ti-N films have induced intensive, worldwide research activities because of their excellent oxidation resistance and good abrasion resistance.The chemical composition of Ti-Al-N and W-Ti-N films can be easily controlled by changing the position of matrix during the magnetron sputtering process,making a greatly simplified of the research process and significant reduce in cost.Series of Ti-Al-N and W-Ti-N films with different chemical composition were fabricated on stainless steels by changing relative positions of substrates to the targets using double-targeted reactive magnetron sputtering,while without considering the thickness of the films under the same process.The mechanism for lubricating and wear resistance is studied on the basis of the analysis and determination of the hardness, surface roughness,friction coefficient and wear rate of films.The results are shown as below:1.For series of Ti-Al-N films:(1) EDS spectrum indicated that when the molar ratio of Ar to N2 is 3:1,the chemical composition and the substrate relative positions had a linear relationship in the range of Ti0.82Al0.18N～Ti0.12Al0.88N.The results of XRD showed that the films deposited near Ti target,the primary microstructure is hexagonal,while in other positions,such as in the middle position and the place near the Al target,cubic,is the primary microstructure.In addition,AlTi2N is the main compounds in hexagonal phase, and as for cubic phase,is TiN.(2) Coexistence of two hard phases TiN and TiAlN in the films deposited in middle position between two targets,and posses the highest hardness value of 35.5GPa in all the prepared films.Analysis of surface morphology and roughness indicated that the films deposited near the targets showed high roughness,and grains in these films have a prymid-like structure.However,for the films deposited in middle position between two targets,the surface is rather smooth,and the grains are relatively smaller and mainly exhibit granner-like or cylinder-like structures.(3) Results of friction and wear tests under room and high temperature indicated that the film deposited in middle position with Al content as 0.65 had the best tribological performance.Study on mechanism at room temperature showed that the formation of transfer layer in films caused by its high hardness value made it the different mechanism from others.2.For series of W-Ti-N films:(1) Composition analysis results indicated that when the molar ratio of Ar to N2 is 3:1,the chemical composition and the substrate relative positions had a linear relationship in the range of W0.80Ti0.20N～W0.18Ti0.82N.The results of XRD showed that different phase structure existed in the W-Ti-N films prepared in various positions,such as TiN,TiN0.6O0.4,W2N and W.After heat treatment,particles of the films uniformly refined and orderly,the surface of thin films become smooth.(2) The W-Ti-N film deposited in position P4 in the whole system has the highest hardness(29.8GPa) and elastic modulus(277.5 GPa),with membrane-based binding maximum to 49N,indicatin a better mechanical properties of these thin films at P4. Surface morphology analysis showed that the surface of W-Ti-N film prepared in the middle position is relatively smooth,and the grains are much smaller and primarily formed with a granner structure.(3) Friction and wear experiments indicated that the film deposited in the middle position with Ti content of x=0.52 had the best tribological performance under room temperature.In all the prepared W-Ti-N thin films,those deposited in the P4 position exhibited the minimum value of friction coefficient and film wear rate.SEM images further proved that the grinding marks are much smooth,while with abrasive wear dominated.So,it exhibited the best friction and wear properties in the entire W-Ti-N films system by comprehensive analysis.
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