Resarch On Microstructure,Mechanical And Tribological Properties Of Tan Based Nanocomposite Films

Hard film technology is an important means for surface modification of tools and tooling materials.Tantalum nitride?TaN?films with high hardness and good wear resistance are important components of hard film materials.However,with the development of manufacturing technology,binary TaN films have not been able to meet the most stringent service requirements.?1?TaWN film:The TaWN films consisted of fcc-?Ta,W?N phase and hcp-?Ta,W?N phase below 22.8 at.%W;when the W content above 22.8 at.%,films consisted of fcc-?Ta,W?N phase,hcp-?Ta,W?N phase,fcc-W2N phase,fcc-W phase.The microhardness of the TaWN films increased initially and then decreased with the increase of W content,the maximum value was 32.2 GPa at 16.2 at%W.The microhardness enhancement was attribute to solid solution strengthening and the change of phase structure.The average friction coefficient and wear rate of TaWN films decreased gradually with the increasing of W content.?2?TaCN film:When the C content was lower than 3.6 at.%,the phase structure of TaCN film consists of fcc-Ta?C,N?and hcp-Ta?C,N?;when the C content was higher than 3.6 at.%,The phase structure consisted of fcc-Ta?C,N?,hcp-Ta?C,N?,CNx and C,and the content of CNx and C phase increased with the increase of C content.With the increasing of C content,the hardness,elastic modulus,H/E and H³/E*² show that firstly increased then decreased,the maximum value were 33.1 GPa,358.1 GPa,0.092 and 0.221 GPa at 12.3 at.%C,respectively.The friction coefficient and wear rate of TaCN films decreased initially then increased with the increase of C content at room temperature,the minimum value were 0.48 and 5.3×10^-8mm³N^-1mm^-1 at 12.3 at%C,respectively.When the increase of the test temperature,the friction coefficion and wear rate of TaCN films decreased,it indicated C elemant can not improve the friction and wear properties of TaCN films at high temperature.?3?TaMgN film:When the Mg content was lower than 8.6 at.%,the TaMgN film consisted of two phases fcc-?Ta,Mg?N and hcp-?Ta,Mg?N;when the Mg content was higher than 8.6 at.%,the TaMgN film was composed of fcc-?Ta,Mg?N,hcp-?Ta,Mg?N and hcp-Mg three-phase composition.With the increasing of Mg content,the hardness,elastic modulus,H/E and H³/E*² show that firstly increased then decreased,the maximum value were 3GPa,376GPa,0.088 and 0.255 GPa at 8.6 at.%Mg,respectively.The friction coefficient and wear rate of TaMgN films decreased initially then increased with the increase of Mg content at room temperature,the minimum value were 0.66 and 1.04×10^-77 mm²/N at 8.6 at%Mg,respectively.When the increase of the test temperature,the friction coefficion of TaCN films increased firstly then decreased,the maxmium value was 0.86 at 400?,however,the wear rate decreased gradually with the increase of temperature,This was mainly related to MgO,Ta₂O₅,TaO₂ oxides produced under high temperature friction.