The contradiction between the strength and ductility of metallic materials is a major scientific problemthat has been researched for a long time. Dual-phase equiatomic and non-equiatomic Ti-Zr-Nb-Ta highentropy alloys...The contradiction between the strength and ductility of metallic materials is a major scientific problemthat has been researched for a long time. Dual-phase equiatomic and non-equiatomic Ti-Zr-Nb-Ta highentropy alloys (HEAs) with super-high strength and excellent ductility have been successfully developedvia mechanical alloying (MA) combined with spark plasma sintering (SPS) technology. This is adjustedby altering the atomic ratios of the different phases. X-ray diffraction (XRD) and transmission electronmicroscopy (TEM) were performed to confirm the dual-phase microstructure. After the SPS process, theaverage grain size of the aforementioned equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs (134 ± 50 nm) evaluated byelectron back-scattering diffraction (EBSD) is smaller than that of the Ti-Zr-Nb-Ta HEAs (150 μm), whichwere fabricated using arc melting. According to the Hall-Petch formula, the grain boundary strengthening contribution in the Ti-Zr-Nb-Ta system is 33-fold higher than those fabricated using the arc-meltingprocess. When the alloy phase comprises the equivalent dual-phase, equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAshave good comprehensive performance compared to non-equiatomic Ti-Zr-Nb-Ta HEAs prepared usingthe same process. The yield strength of equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs (2212 ± 38 MPa) is two-foldhigher than that of Ti-Zr-Nb-Ta HEAs (1100 ± 90 MPa) fabricated via arc melting. This can be attributed tothe ultra-fine grain size. Notably, the equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs possess approximately the samebiocompatibility as commercial pure Ti (CP-Ti), indicating that the equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs areprovided with a possibility as an advanced biomaterial for the applications of the medical field.展开更多
基金The work was financially supported by the National Natural Science Foundation of China(No.51871077)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515012626)+3 种基金the Shenzhen Knowledge Innovation Plan-Fundamental Research(Discipline Distribution)(No.JCYJ20180507184623297)the Shenzhen Science and Technology Plan-Technology Innovation(No.KQJSCX20180328165656256)the Development and Reform Commission of Shenzhen Municipality-Shenzhen R&D Center for Albased Hydrogen Hydrolysis Materials(No.ZX20190229)the Startup Foundation from Shenzhen and Startup Foundation from Harbin Institute of Technology(Shenzhen).
文摘The contradiction between the strength and ductility of metallic materials is a major scientific problemthat has been researched for a long time. Dual-phase equiatomic and non-equiatomic Ti-Zr-Nb-Ta highentropy alloys (HEAs) with super-high strength and excellent ductility have been successfully developedvia mechanical alloying (MA) combined with spark plasma sintering (SPS) technology. This is adjustedby altering the atomic ratios of the different phases. X-ray diffraction (XRD) and transmission electronmicroscopy (TEM) were performed to confirm the dual-phase microstructure. After the SPS process, theaverage grain size of the aforementioned equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs (134 ± 50 nm) evaluated byelectron back-scattering diffraction (EBSD) is smaller than that of the Ti-Zr-Nb-Ta HEAs (150 μm), whichwere fabricated using arc melting. According to the Hall-Petch formula, the grain boundary strengthening contribution in the Ti-Zr-Nb-Ta system is 33-fold higher than those fabricated using the arc-meltingprocess. When the alloy phase comprises the equivalent dual-phase, equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAshave good comprehensive performance compared to non-equiatomic Ti-Zr-Nb-Ta HEAs prepared usingthe same process. The yield strength of equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs (2212 ± 38 MPa) is two-foldhigher than that of Ti-Zr-Nb-Ta HEAs (1100 ± 90 MPa) fabricated via arc melting. This can be attributed tothe ultra-fine grain size. Notably, the equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs possess approximately the samebiocompatibility as commercial pure Ti (CP-Ti), indicating that the equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs areprovided with a possibility as an advanced biomaterial for the applications of the medical field.
