Effect Of Al Content On Microstructure And Properties Of FeCrMnAlCu High Entropy Alloy

In the mid-1990s,Professor Ye Junwei put forward the concept of multi-principal component high entropy alloy,and proposed that the alloy is no longer composed of a single element,but includes many elements.Compared with traditional single element alloys,this alloy has higher mixing entropy,that is,the confusion of atomic arrangement in the alloy system is high,which promotes the elements in the alloy system to form simple crystal structure phase or even amorphous state,and is not conducive to the formation of brittle intermetallic compounds.In terms of properties,multi-principal component high entropy alloy is better than traditional alloy,such as high strength,high hardness,high temperature resistance,good corrosion resistance and wear resistance.The development of high entropy alloys opens the door to design new alloys,and provides a huge development space for its theoretical research and industrial application.FeCrMnAlCu system high entropy alloys were prepared by vacuum arc smelting technology by selecting relatively inexpensive elements such as Fe,Cr,Mn,Al and Cu as the main elements of high entropy alloys.The effects of Al content on phase structure,microstructure,hardness,wear resistance and compressive strength of Fe Cr Mn Al_xCu（x=0,0.5,1.0,1.5,2.0）high entropy alloy were investigated by XRD,SEM,EDS,TEM,microhardness tester and friction tester.The experimental results showed that FeCrMnAlCu high entropy alloy was composed of simple BCC and FCC two phases.With the increase of Al content,the BCC phase in Fe Cr Mn Al_xCu high entropy alloy increased gradually,as well as the content of nano-scale Cu-rich precipitates in BCC phase,and the hardness of Fe Cr Mn Al_xCu high entropy alloy.Fe Cr Mn Al_xCu high entropy alloy had good wear resistance.When Al=1.5,the comprehensive properties of the alloy was the best.The hardness was 489.6 HV,the yield strength was 1286.72 MPa,the compressive strength was 1908.80 MPa,and the deformation rate was 9.05%.Compared with similar high entropy alloys,FeCrMnAlCu high entropy alloys had higher cost performance.The effects of the change of Al content on the phase structure,microstructure,hardness,wear resistance and compressive strength of Fe Cr Mn Al_xCu high entropy alloy and the effects of the change of Fe content on the phase structure,microstructure,hardness,wear resistance and compressive strength of Fe_xCr Mn Al Cu high entropy alloy were studied.Taking Fe and Al as joint variables,the contents with the best comprehensive properties were selected and fine-tuned.The microstructure,microstructure,hardness,tribological and compressive properties of Fe_（2-y）Cr Mn Al_yCu（y=1.3,1.4,1.5,1.6,1.7）high entropy alloys were examined and analyzed.The experimental results showed that the interdendritic structure and dendrite structure of Fe_（2-y）Cr Mn Al_yCu high entropy alloy were composed of BCC phase,and the ordered BCC phase Fe Al intermetallic compound was precipitated in the dendrite,and the precipitate content increased slightly with the decrease of Fe content and the increase of Al content,which made the hardness of Fe_（2-y）Cr Mn Al_yCu high entropy alloy increased continuously.When y=1.6,the hardness of the alloy was 558.5 HV,the yield strength was1205.43 MPa,the compressive strength was 1431.52 MPa,and the deformation rate was9.06%.With the decrease of Fe content and the increase of Al content,the problem of element segregation in the alloy has been alleviated to some extent.