Abstract:In this experiment, CoCrFeMnNiTix (x=0, 0.2, 0.4, 0.6) high entropy alloys were prepared by vacuum arc melting and casting method in high-purity argon atmosphere. As a typical alloy, CoCrFeMnNi high entropy alloy showed good ductility but low strength, so the aim of this experiment was to improve its strength by adding Ti element. Three main phases were found in the prepared CoCrFeMnNiTix HEAs: FCC phase, Laves phase and nanoparticle phase. The microhardness of the alloys increased from HV 244 to HV 785 with Ti increased. For CoCrFeMnNiTi0.6 alloy, the yield strength, compressive strength and plastic strain were 1034 MPa, 2333 MPa and 23%, respectively. The addition of Ti would have a good solid solution strengthening effect, which improved the strength of the alloys significantly but reduced the ductility. Laves phase was benefical for the strength of the alloys but harmful for the ductility.
Keywords: CoCrFeMnNiTix; high entropy alloy; strengh; ductility