Effect of Co content on microstructure and mechanical properties of CoxCr25(AlFeNi)75-x high entropy alloy
In view of the low yield strength of FCC based TRIP high entropy alloy,CoxCr25(AlFeNi)75-x alloy system was designed and prepared to achieve the synergy between precipitation strengthening of B2 phase and FCC-HCP type deformation induced transformation.The effect of Co content on the microstructure and mechanical properties of the alloy system was investigated using a method combining thermodynamic simulation and experiment.The results show that with the increase of Co content,the precipitated B2 phase in the alloy gradually decreases,resulting in a decrease of yield strength.The yield strength of Co45 Cr25 Al10 Fe10 Ni10 alloy is about 850 MPa,while the yield strength of Co57 Cr25 Al6 Fe6 Ni6 alloy decreases to less than 500 MPa.On the other hand,with the increase of Co content,deformation induced FCC-HCP martensitic transformation occurs in Co51 Cr25 Al8 Fe8 Ni8 and Co57 Cr25 Al6 Fe6 Ni6 alloys during tensile test,which makes them have good plasticity close to 50％.
high entropy alloymechanical propertiesprecipitation strengtheningdeformation induced transformation
万方数据
