Preparation And Properties Of Multi-component Nano-composite Ti-based Nitride Coatings

In this paper,TiVN and TiAl VN nanocomposite coatings with different V contents were prepared by DC magnetron sputtering technology and high-power pulsed magnetron sputtering technology.The purpose was to study the effect of V element doping on the microstructure and properties of the coatings.By comparing the macroscopic morphology,microstructure,and mechanical properties of the coatings,the optimal process parameters for preparing the coatings are determined,and the process parameters for the target coatings required for the experiments are determined on the basis of this.The surface morphology,cross-section morphology,elemental composition and phase structure of the coating were characterized by field emission scanning electron microscope,energy spectrometer and X-ray diffractometer.The nano-indenter,T3000 friction and wear tester and SGM M8/10 A artificial intelligence box resistance furnace were used to test the coatings’ hardness,elastic modulus,binding force,friction and wear performance and high temperature oxidation resistance.The results are as follows:DC magnetron sputtering technology was used to prepare TiVN coatings with different V contents by controlling the V target power.Research indicates that TiVN coatings always maintain a single face-centered cubic structure.When the V content is 2.44%,the hardness and Young’s modulus of the TiVN coating are the largest,which are 36.68 GPa and 371.77 GPa,respectively.All coatings have good adhesion.At room temperature,the wear scar width and wear rate of TiVN coatings decreased significantly with increasing V content,and the average friction coefficient decreased with increasing V content.It has the best friction and wear resistance when the V content is 14.36%.TiAl VN coatings with different V contents were prepared by co-sputtering of V target and TiAl alloy target.Research shows that the TiAl VN coating is mainly composed of TiN,Al N,and VN phases,and has a face-centered cubic structure.The hardness of TiAl VN coating decreases first and then increases with increasing V content,and the elastic modulus of the coating gradually increases.When the V content is 11.02%,the TiAl VN coating has the best hardness and elastic modulus,which are 25.07 GPa and 343.82 GPa,respectively.At room temperature,the average friction coefficient of TiAl VN coating decreases with the increase of V content,and then increases.When the V content is 11.02%,the TiAl VN coating has the lowest friction coefficient about 0.5884.The coating has the best comprehensive mechanical properties.The TiAl VN coatings were prepared by high-power pulsed magnetron sputtering technology.Studies shows that when the power is 15 k W,the V element content in the TiAl VN coating was 10.37%.The average coefficient of friction at room temperature was 0.6055.The TiAl VN coating has better surface morphology,the surface roughness of the coating is about 10 nm,and it has a good bonding force.The TiAl VN coating is still face-centered cubic structure with a preferred orientation(200)crystal plane.Friction and wear experiments showed good resistance to friction and wear.The friction coefficient changed steadily,mainly with abrasive wear and adhesive wear.900oC constant temperature thermal oxidation test results show that High power pulsed magnetron sputtering TiAl VN coating has high density and good oxidation resistance.The oxide layer with a pore structure formed after the coating is oxidized provides a channel for oxygen to diffuse into the substrate,causing oxidation of the substrate.The main reason for the failure of the coating is the cracks in the coating and the shedding of the coating,mainly due to the residual stress generated during the deposition process,the thermal stress caused by the mismatch of thermal expansion and the oxidation of the substrate.