Study on Microstructure and Mechanical Properties of Brazed Joint of CoCrFeMnNiTi_X High Entropy Alloys

Three kinds of high entropy CrCoFeMnNiTi_X alloys were brazed with the same material using BNi2 solder under vacuum condition. The microstructure and mechanical properties of brazed joints were studied by scanning electron microscope, energy spectrum analysis and shear test. The results show that three CoCrFeMnNiTi_X high entropy alloys can be brazed well under the selected welding process parameters. The vacuum brazing joints of the three alloys can be divided into three zones: brazing zone, diffusion affected zone and base metal, and a layer rich in Cr is formed in the center of the brazing zone. The shear strength of brazed joint increases with the increase of Ti content of base metal. For the high entropy Cr₁₉Co₁₉Fe₁₉Mn₁₉Ni₁₉Ti₁₀ alloy with the highest Ti content, the average shear strength of the brazed joint is 188.76 MPa when the brazing temperature is 1000 ℃ and the holding time is 20 min.