Structure And Properties Of (AlSiTiCrNbV)N Films Deposited By Magnetron Sputtering And Its Application In Cutting Tools

In recent years,high-entropy alloys?HEAs?with excellent comprehensive properties have attracted more and more attention in the processing and manufacturing industry.The preparation of HEA coating materials by laser cladding,thermal spraying or vapor deposition have been widely studied.But up to now,the coating materials still have some problems,such as low hardness,poor adhesion,and the application in the field of tool materials,have not been reported publicly.In this paper,?AlSiTiCrNbV?N HEA thin films were prepared by magnetron sputtering,and their microstructure,mechanical properties and wear resistance were studied.Also,the wear properties of several different coated tool materials were compared,and the surface roughness of the workpiece after cutting was analyzed,which could provide experimental support for the application of HEA coating materials in cutting tools.The AlSiTiCrNbV HEA targets were prepared by vacuum arc melting,and the?AlSiTiCrNbV?N HEA thin films were deposited on different substrates by adjusting the parameters of magnetron sputtering.The effects of sputtering power,sputtering time,N₂ flow rate and negative bias on the microstructure,mechanical properties and wear resistance of HEA films were studied.The following results were obtained:The AlSiTiCrNbV HEA target mainly showed a single FCC solid solution structure without the formation of amorphous and intermetallic compounds.Increasing the sputtering power or prolonging the sputtering time could cause a change from amorphous structure to single FCC solid solution structure for the?AlSiTiCrNbV?N HEA film,making the film surface smoother and denser.The sputtering power mainly affects the size of the grain,and the grain size could be increased by 2 to 3 times with the increase of power;the sputtering time mainly affects the crystal structure,and the microstructure of the obatined films was changed from an amorphous structure to a crystal structure by prolonging time.As the sputtering time and power increased,the thickness of the films also increased.Increasing the negative bias voltage could enhance the energy of the ion bombardment into the substrate,promote crystal nucleation,and make the surface of the films denser and smoother.Sputtering power,sputtering time,N₂ flow rate and negative bias had a significant positive correlation on the hardness of?AlSiTiCrNbV?N HEA films in a limited range;as the sputtering power was 200 W,sputtering time was 60 min,N₂ flow rate was 15 sccm,and negative bias voltage was 150 V,the microhardness of the film reached a maximum value of 56 GPa;the HEA film was prepared by using Cr/CrN as the transition layer,the friction coefficient and bonding force were 0.53 and 98 N,respectively.The?AlSiTiCrNbV?N HEA film was prepared on the cemented carbide tool.Comparing with the traditional TiN and TiAlN tool coating materials,the wear loss and surface roughness of?AlSiTiCrNbV?N HEA coated tool were better than that of the uncoated tool and the TiN coated tool.