Study On The Organization Adjustment,Mechanical And Corrosion Properties Of AlCr_yFeNi₂Cu_x High-entropy Alloy

In the 1990s,Taiwan scholar Ye Jun-wei broke the traditional alloy design model,and proposed the concept of high-entropy alloy.Due to its simple solid solution structure and superior mechanical properties,high entropy alloys have been widely concerned since they were proposed.The composition design of high entropy alloys and the effect of elements on their microstructure and mechanical properties have been the core problem of high entropy alloy research field.Therefore,it is significantly to study the effect of the content of certain elements on the microstructure and mechanical properties of high-entropy alloys.High entropy alloy is a rich treasure with academic research and industrial development potential,which can develop a lot of high-tech materials,and high entropy alloy can be parpared into block,coating or film using traditional casting,forging,powder metallurgy,spraying and coating method.AlCrFeNi high entropy alloys have been widely studied because of their excellent microstructure,however,the research on the effcet of Cu,Cr element and TiC content changes on microstructure and properties of AlCrFeNi high entropy alloys have not investigate deeply,and the research on the corrosion resistance of the alloy is not mentioned either.Therefore,the effect of Cu,Cr and TiC content changes on the microstructure and properties of AlCryFeNi2Cux-TiC2 high entropy alloys were investigated.The effect of Cu,Cr,TiC content change on the microstructure and properties of AlCryFeNi2Cux-TiC2 high entropy alloys were studied by Peeling corrosion test,intergranular corrosion test,Polarization curve test,impedance test(EIS),X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM),electron back scattering diffraction test results with electron backscattered diffraction(EBSD),general hardness tester(UH250)and electronic universal testing machine(MTS-E45).It is found that AlCryFeNi2Cux high entropy alloy is mainly composed by FCC phase and BCC phase.In AlCrFeNi2Cux high entropy alloy,with the increase of Cu element,Cu tends to aggregate and is wrapped with dendritic crystals.When the content of Cu is 1.6 at.%,the comprehensive performance of the alloy is the best,the Vickers hardness,compressive strength,yield strength,compression ratio,the corrosion potential and self-corrosion current density were 372HV?2256MPa?669MPa?40.5%?-0.30Vand 2.31?A/cm2,respectively.In AlCryFeNi2Cu1.6 high entropy alloys,with the increase of content of Cr,Cu by parcel dendrite into evenly distributed in the interdendritic,when Cr content is 2.0 at.%,the comprehensive performance of the alloy is the best,the Vickers hardness,compressive strength,yield strength,compression ratio,the corrosion potential and self-corrosion current density were 402.7HV,2252MPa,815MPa,30.5%,-0.30V and 0.52?A/cm2,respectively.In TiC/AlCr2FeNi2Cu1.6 high entropy alloys composite materials,Al,Ni and Cu phases are formed with the addition of TiC.The phase grows gradually and the concentration of each element increases.When the content of TiC increases,TiC agglomeration occurs,when the TiC content is 7.5 vol%,the alloy has the best comprehensive performance,its Vickers hardness,compressive strength,yield strength,compression rate,self-corrosion potential and self-corrosion current density were 477HV,1943MPa,1213MPa,8.32%,-0.29V and 0.32?A/cm2,respectively.