The Deposition And Investigation On Properties Of AlCrN Base Coatings By High Power Impulse Magnetron Sputtering And Arc Ion Plating

In order to meet the severe requirements of cutting tools using for high speed yet dry machining,this study aims to improve mechanical properties,oxidation resistance and wear resistance of AlCrN base hard coatings.First,high power impulse magnetron sputtering?HIPIMS?was used to prepare the AlCrN coating.The deposition parameters were optimized.Second,the other elements were incorporated into the AlCrN to improve the service performance of the coating.Second,based on the optimized AlCrN,both O and Si elements were incorporated into the coating by HIPIMS.The Si element addition was used to fabricate a nanocomposite structure to enhance the mechanical properties of the coating.In addition,the O element addition prefered to reduce the friction coefficient,improve both wear resistance and high-temperature oxidation resistance of the coating.The influence of incorporating O and Si elements on the coating structure and performance were researched.Third,both the HIPIMS and the Arc Ion Plating?AIP?were applied to prepare the Si and V added AlCrSiVN nanocomposite coatings.The co-addition of the Si and the V elements keep the excellent mechanical properties and oxidation resistance of the AlCrN coating.The effect of the V addition to the evolution of the coating structure and properties was investigated.The V component reduced the friction coefficient of the AlCrSiVN coating via the formation of lubricant oxides.Four,since the excellent properties of AlCrSiN?high mechanical property,superior oxidation resistance and wear resistance?and VN?low friction coefficient?coatings,the AlCrSiN/VN nanomultilayer coatings with high wear resistance and low friction coefficient were fabricated.The main conclusions obtained in this work are listed as followings.1)The HIPIMS technology was used to prepare the AlCrN coating in an Ar/N₂atmosphere.The coating with excellent mechanical properties was obtained by adjusting the deposition bias.With the increase of the substrate bias,the average sizes of particles on the coating surface decrease gradually.The hardness,elastic modulus and adhesion of the coating first increases then decreases with the bias rise.The hardness reaches the maximum value of 32.5±2.0 GPa as the bias increased to-150V.However,the film adhesion strength reaches the maximum value of 40 N when the bias was set at-100 V.2)Based on the AlCrN coating by HIPIMS,both AlCrSiN and AlCrSiON coatings were prepared.The influence of oxygen content on coating structure,mechanical properties and tribological properties of coatings were studied.As the amounts of O in the coating increase,the hardness of the coating increases first and then decreases.The maximum value of 20.1±3.0 GPa was achieved when the content of O is 24.3at.%.The adhesion strength of the AlCrSiON coating increases with the increase of oxygen content.The maximum value of the critical load is 90 N when the oxygen content is 30.4 at.%.At RT-600?,the friction and wear experiment results show that the AlCrSiON coating possesses the best wear resistance when the oxygen content was added up to 30.4 at.%.3)AlCrSiVN coating was deposited by HIPIMS and AIP on cemented carbides in the mixture atmosphere of N₂ and Ar.As the V target power?HIPIMS?increases from0 to 2 kW,the content of the V element in the coating increases from 0 to 7.5 at.%.The influence of V content on the microstructure,mechanical properties and friction properties of the coating was studied.According to the experiment,with the V element content of the AlCrSiN coating increasing from 0 to 7.5 at.%,the hardness of the coating decreased from 34.0±1.1 to 26.3±2.4 GPa.High-temperature friction and wear experiments were conducted under room temperature-600?.At room temperature,the friction coefficient of the AlCrSiVN coating varied in the range of0.68-0.73.The friction coefficient of the coating decreased 0.66 as the V content in the coating increased up to 7.5 at.%.Under the high temperatures,the AlCrSiVN coating reveals a lower average friction coefficient compared to the AlCrSiN,owing to the lubricant oxide V₂O₅ formed on the V added coating surface.4)Because of the low friction coefficient of the VN coating and good wear resistance of the AlCrSiN coating,this AlCrSiN/VN multilayer coating was designed and fabricated.The AlCrSiN/VN multilayer coating was deposited by HIPIMS and AIP together.Varying the V target power of HIPIMS?0-2.5 kW?was used to adjust the thickness of the VN interlayer.With the increase of the V target power,the critical load of the coating gradually increases.The hardness of the multilayer coating reveals the maximum value of 29.9±0.9 GPa when the V target power is 2.0 kW.At RT-700?,the tribological experiment results show that when the V target power is2.0 kW,the coating possesses the lowest friction coefficient and the highest wear resistance.