A Study On The Microstructure And Property Of AlCoCuFeMnNi-M Multy-principal-element Alloys

Multi principal element alloys refer to those contain at atleast five main elements, and each kind of elemental atoms do not exceed percent50%.Multi principal element alloys cause great research attention for its excellent comprehensive performance at the first time it was pulished.In this paper,AlCoCuFeMnNi multi principal element alloys were prepared by vacuum non-comsumable arc-melting.Although Cu element in the interdendritic have slight enrichment,the DSC and EDS test result reveals that the uniform their tissue constituents.In this Study,the XRD test results in that AlCoCuFeMnNi multi principal element alloys are composed by simple BCC and FCC phases.The hardness distribution of AlCoCuFeMnNi multi principal element alloy is uniform, which varies in 390HV0.2 or so, and its dry friction performance is excellent because of the stable friction coefficient which is 0.46.AlCoCuFeMnNi multi principal element alloy has excellent properties, but at the same time alloy components containing the higher priceelementsCo and Ni. In order to reduce the cost, promote the practical application of the alloyr,AlCoCuFeMnNi-M high-entropy alloy was prepared on the cast iron HT250 and Q235 steel substrate by plasma cladding technology. SEM and EDS analysis results of AlCoCu FeMnNi show that in HT250 matrix of the organization and composition of alloy coating prepared by complex and matrix elements Fe and C will be more integrated into the alloy coating, and forming the controllability is poor.Microstructure of the coating of the AlCoCuFeMnNi multi principal element alloy on Q235 steel substrate is uniform, and it is suitable for wide application.Microstructure and properties of AlXCoCuFeMnNi multi principal element alloy coating with different Al content were studied to reveal the transition mechanism of the AlCoCuFeMnNi multi principal element amorphous alloy in BCC and FCC. XRD results show that the Al content changes can not only change the alloy phase structure, but also change the FCC grain preferred orientation. Comprehensive analysis shows that the FCC to BCC transition mechanism is formed after the addition of Al alloy metal between compounds and BCC crystal structure elements combination, formed a BCC crystal structure of the solid solution. And the microhardness of AlXCoCuFeMnNi alloy coating increased significantly with the increase of Al element content.AlXCoCuFeMnNi multi principal element alloy coating with different Al content were prepared on Q235 steel substrate,and the SEM test results showed that the alloy dendrites are weakening.In order to strengthen the dendriteand improve the comprehensive performance of AlCoCuFeMnNi alloy coating, different mass fractions of WC powder（10%, 20%, 30%）,rare earth CeO₂（0.5%, 1.0%, 1.5%） and the mixed molar ratio instead of Ni Ni60 A powder were added during the preparation of AlCoCuFeMnNi alloycomposite coating.The experimental results show that the microstructure of the alloy is obviously strengthened, and the hardness value is improved, and the effect of 30%（WT） WC powder and Ni60 powder is the most obvious. In this study we found that CeO₂ refinement AlCoCuFeMnNi multi principal element alloy grain mechanism is different in the refinement of the Fe based alloy non spontaneous shaped nuclear mechanism, but CeO₂ in the crystallization front enriched, prevent grain growth, so that grain refinement.