A Study On Effects Of Magnetron Sputtering Upon Oxide Films From High Entropy Alloys

In recent years,high entropy alloy films have attracted more and more attention due to their excellent properties.There are many researches on high entropy alloys,which lay a foundation for the development of high entropy alloy films.For the research of high entropy alloy films,most of them are to explore the influence of doping a certain element on the properties of high entropy alloy films or the influence of nitrogen flow rate on nitride films.There are few reports on high entropy alloy oxide films.Therefore,based on improving the mechanical properties of films,this paper explores the influence of preparation parameters on the quality of films.In this paper,high entropy alloy oxide films were prepared on monocrystalline silicon substrate by magnetron sputtering,(FeCrCoNiMn)O_x films and(FeCrCoNiMn)O_x oxygen concentration gradient films were prepared by single target process,and(FeCrCoNiMnAl_x)O films and(FeCrCoNiMnAl_x)O aluminum composition gradient films were prepared by double target process.The composition,phase,morphology,film substrate bonding force,hardness and elastic modulus of the films were characterized by EDS,XRD,SEM,scratch tester and nano indentation tester,and the effect of magnetron sputtering process on the film quality was studied.The research results are:(1)(FeCrCoNiMn)O_x thin films were prepared by single target at different oxygen concentration(0～20 vol%),substrate temperature(20～350℃)and sputtering power(90W、120 W、150 W).The film was FCC structure.With the increase of oxygen concentration,the bonding strength,hardness and elastic modulus of the film substrate first increased and then decreased.When the oxygen concentration was 5%,the film had the best performance;With the increase of substrate temperature,the bonding force,hardness and elastic modulus of the film substrate gradually increase,and the performance was best at 350℃;With the increase of sputtering power,the film substrate adhesion gradually increases,and the hardness and elastic modulus first increase and then decrease.Compared with ordinary FeCrCoNiMn high entropy alloy films,the addition of oxygen atoms enhances the solid solution strengthening effect.The optimum process parameters are:oxygen concentration is 5%,substrate temperature is 350℃,and FeCrCoNiMn target sputtering power is 150 W.(2)(FeCrCoNiMnAl_x)O thin films with different Al target sputtering power were prepared by using double targets.The addition of Al makes the structure change from FCC to BCC.The addition of Al enhances the mechanical properties of the films.With the increase of Al target sputtering power,the bonding force,hardness and elastic modulus of the film substrate first increase and then decrease.The best performance is obtained when the power is 55 W.(3)On the basis of(FeCrCoNiMn)O_x thin films and(FeCrCoNiMnAl_x)O thin films,(FeCrCoNiMn)O_x oxygen concentration gradient films and(FeCrCoNiMnAl_x)O aluminum composition gradient films were prepared.The effects of oxygen concentration gradient and aluminum composition gradient on the mechanical properties of the films were investigated.With the increase of the number of oxygen concentration gradient films,the properties of the films are gradually improved,and the mechanical properties of the oxygen concentration gradient three-layer films(the surface oxygen concentration is 10%)are the best;With the increase of the number of aluminum composition gradient films,the bonding force,hardness and elastic modulus of the film substrate increase first and then decrease.The mechanical properties of aluminum composition gradient bilayer films(the sputtering power of the surface Al target is 55 W)are the best.