As-cast microstructure and properties of non-equal atomic ratio TiZrTaNbSn high-entropy alloys

Abstract

High-entropy alloys have been proved to be potential candidate materials in the biomedical field due to their balanced mechanical properties and excellent biocompatibility. The effects of atomic ratios on the as-cast microstructural evolution, mechanical properties, and electrochemical property of TiZrTaNbSn high-entropy alloys were studied systematically. The crystal structure of TiZrTaNbSn high-entropy alloys is single BCC phase, and the microstructural evolution is based on atomic ratio. The dendric structure, peritectic structure, pseudo eutectic and equiaxed grain, which are associated with element segregation, can be obtained by non-equal atomic ratio. Ti30Zr20Ta20Nb20Sn10 alloy demonstrates a high compressive strength and fracture strain, which are 2,571.8 MPa and 12%, respectively, and the fracture behavior is quasi-cleavage faults. The Ti45Z35Ta5Nb5Sn10, Ti30Zr20Ta20Nb20Sn10 and Ti35Zr25Ta15Nb15Sn10 alloys show excellent corrosion resistance according to Nyquist diagram, polarization curves and corrosion morphology. Compared with TiZrTaNbSn alloy, the corrosion rate of Ti45Zr35Ta5Nb5Sn10 alloy increases by about 98.9%. It can be concluded that non-equal atomic ratios are effective for microstructure control and performance optimization.