Study On The Composition Optimization Design Of FeCrNiCoTi High Entropy Alloy And The Influence Of WC On It's Performance

High-entropy alloy generally refers to an alloy material composed of five or more metal elements in a molar ratio.Generally,a solid solution phase having a simple crystal structure is formed,and effects such as solid solution strengthening,dispersion strengthening,and fine grain strengthening are produced in terms of performance.Therefore,most high-entropy alloys have excellent properties such as high hardness,good wear resistance,and good corrosion resistance.In this paper,the composition and properties of FeCrNiCoTi high-entropy alloy were optimized by orthogonal experimental design.The optimal combination of different WC content for orthogonal analysis of Fe0.7Cr0.7Ni0.4Co13Ti1.0 high-entropy alloy was studied.Performance impact.Five kinds of metal element powders of Co,Cr,Fe,Ni and Ti with purity of 99.99%nd WC particles were selected.According to the orthogonal experimental design scheme(five factors and four levels),the FeCrNiCoTi high-entropy alloy was prepared by vacuum hot pressing sintering.The sample,Fe0.7Cr0.7Ni0.4Co1.3Ti1.0/WCx high-entropy alloy sample(x is a mass percentage,respectively 5%,15%,25%,35%).Metallographic microscopy(OM),X-ray diffractometry(XRD),scanning electron microscopy(SEM)and energy spectrum analysis(EDS)were used to characterize the microstructure,and Vickers hardness,corrosion resistance and Related performance tests such as friction and wear.The experimental results show that the prepared FeCrNiCoTi high-entropy alloy has typical dendritic and interdendritic structure,and its crystal structure is FCC and BCC structure;Fe0.7Cr0.7Ni0.4Co1.3Ti1.0 high-entropy alloy has the highest hardness value,reaching 687 HV;Among the 8 combinations of gold tested,the wear resistance of group f was the best;in 1.0 mol/L H2SO4 solution,the corrosion current density of Fe0.7Cr0.7Ni0.4Co1.3Ti1.0 high-entropy alloy was 2.51 ×10-6 A/cm2,the corrosion potential is-0.786 mV,and the corrosion current density is about three orders of magnitude smaller than the h group with the least corrosion resistance.In 3.5%NaCl solution,the corrosion resistance first increases and then weakens.The corrosion current density of Fe0.7Cr0.7Ni0.4Co1.3Ti1.0 high-entropy alloy is 0.79×10-6 A/cm2,and the corrosion potential is-0.720 mV..After WC is added,the Feo.7Cro.7Nio.aCo1.3Ti10 high-entropy alloy is still a typical dendritic and interdendritic structure.The alloy phase is simple FCC and BCC.With the increase of WC content,the hardness of the alloy increases remarkably.When the WC is 35%,the hardness is at most 779 HV.With the increase of WC content,the friction coefficient decreases continuously.When the WC is 35%,the friction coefficient is nearly double that of the case without WC.Through the corrosion resistance test in 1.0 mol/L H2SO4 solution,it is found that Corrosion resistance decreases with the increase of WC;in 3.5%NaCl solution,with the increase of WC,the corrosion resistance first increases and then weakens.When WC=5%,the corrosion resistance is the best.-0.750 mV,corrosion current density is 7.94×10-7 A/cm2.