Ti-Zr-Hf-Nb-Ta-Sn high-entropy alloys with good properties as potential biomaterials

摘要

(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))_(100-x)Sn_(x)(x=3,5,and 7;at%)high-entropy alloys(HEAs)with good mechanical properties,corrosion resistance,and biocompatibility were developed as potential biomaterials.The effects of Sn additions on the microstructure and properties of the HEAs were investigated.The(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))_(100-x)Sn_(x) with x=3 at%exhibited the single body-centered-cubic(BCC)structure.The HEAs with the further increased Sn contents of x=5 at%and 7 at%were composed of a BCC phase and a hexagonal-close-packed(HCP)-(Sn,Zr)ordered phase.The addition of Sn improved the compres-sive yield strengths and hardness of the HEAs to 1068-1259 MPa and HV 315-HV 390,respectively.These HEAs also possessed relatively low Young's moduli of 80-91 GPa.Among the present Ti-Zr-Hf-Nb-Ta-Sn HEAs,the(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))97Sn3 HEA exhibited the good combination of high yield strength of~1068 MPa,relatively low Young's modulus of 80 GPa,and good plasticity(~45%).The HEAs also possess good bio-corrosion resistance and biocompatibility,parallel to the Ti-6Al-4V alloy.The Ti-Zr-Hf-Nb-Ta-Sn HEAs with the integration of the high yield strength,relatively low Young's modulus,and good corrosion resistance and bio-compatibility are promising for biomedical applications.