Zr was added to Ti−Nb−Fe alloys to develop low elastic modulus and high strengthβ-Ti alloys for biomedical applications.Ingots of Ti−12Nb−2Fe−(2,4,6,8,10)Zr(at.%)were prepared by arc melting and then subjected to hom...Zr was added to Ti−Nb−Fe alloys to develop low elastic modulus and high strengthβ-Ti alloys for biomedical applications.Ingots of Ti−12Nb−2Fe−(2,4,6,8,10)Zr(at.%)were prepared by arc melting and then subjected to homogenization,cold rolling,and solution treatments.The phases and microstructures of the alloys were analyzed by optical microscopy,X-ray diffraction,and transmission electron microscopy.The mechanical properties were measured by tensile tests.The results indicate that Zr and Fe cause a remarkable solid-solution strengthening effect on the alloys;thus,all the alloys show yield and ultimate tensile strengths higher than 510 MPa and 730 MPa,respectively.Zr plays a weak role in the deformation mechanism.Further,twinning occurs in all the deformed alloys and is beneficial to both strength and plasticity.Ti−12Nb−2Fe−(8,10)Zr alloys with metastableβphases show low elastic modulus,high tensile strength,and good plasticity and are suitable candidate materials for biomedical implants.展开更多
A series of ferrite/bainite(F/B) multi-phase steels containing different volume fractions of ferrite were obtained.The effect of soft phase(ferrite) content on the work-hardening behavior of the steel was studied by t...A series of ferrite/bainite(F/B) multi-phase steels containing different volume fractions of ferrite were obtained.The effect of soft phase(ferrite) content on the work-hardening behavior of the steel was studied by the finite element simulation with V-BCC model and the modified Crussard-Jaoul(C-J) analysis.It is shown that the multi-phase steels have an excellent anti-deformation ability,such as higher stress ratio(R t1.5 /R t0.5),higher uniform elongation and lower yield to tensile strength ratio.For the F/B multi-phase steels,increasing the proportion of ferrite would help to increase the uniform elongation.However,introducing much more fraction of ferrite would not be helpful to improve the stress ratio of multi-phase steel.The ferrite plastic strain constrained by bainite would be beneficial to increasing the work hardening rate.The optimum proportion of ferrite will result both higher stress ratio and uniform elongation in multi-phase steel.展开更多
基金the Natural Science Foundation of Shanghai,China(No.15ZR1428400)Shanghai Engineering Research Center of High-Performance Medical Device Materials,China(No.20DZ2255500)the Project of Creation of Life Innovation Materials for Interdisciplinary and International Researcher Development,Tohoku University,sponsored by Ministry,Education,Culture,Sports,Science and Technology,Japan,and the Grant-in Aid for Scientific Research(C)(No.20K05139)from JSPS(Japan Society for the Promotion of Science),Tokyo,Japan.
文摘Zr was added to Ti−Nb−Fe alloys to develop low elastic modulus and high strengthβ-Ti alloys for biomedical applications.Ingots of Ti−12Nb−2Fe−(2,4,6,8,10)Zr(at.%)were prepared by arc melting and then subjected to homogenization,cold rolling,and solution treatments.The phases and microstructures of the alloys were analyzed by optical microscopy,X-ray diffraction,and transmission electron microscopy.The mechanical properties were measured by tensile tests.The results indicate that Zr and Fe cause a remarkable solid-solution strengthening effect on the alloys;thus,all the alloys show yield and ultimate tensile strengths higher than 510 MPa and 730 MPa,respectively.Zr plays a weak role in the deformation mechanism.Further,twinning occurs in all the deformed alloys and is beneficial to both strength and plasticity.Ti−12Nb−2Fe−(8,10)Zr alloys with metastableβphases show low elastic modulus,high tensile strength,and good plasticity and are suitable candidate materials for biomedical implants.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2010CB630801)
文摘A series of ferrite/bainite(F/B) multi-phase steels containing different volume fractions of ferrite were obtained.The effect of soft phase(ferrite) content on the work-hardening behavior of the steel was studied by the finite element simulation with V-BCC model and the modified Crussard-Jaoul(C-J) analysis.It is shown that the multi-phase steels have an excellent anti-deformation ability,such as higher stress ratio(R t1.5 /R t0.5),higher uniform elongation and lower yield to tensile strength ratio.For the F/B multi-phase steels,increasing the proportion of ferrite would help to increase the uniform elongation.However,introducing much more fraction of ferrite would not be helpful to improve the stress ratio of multi-phase steel.The ferrite plastic strain constrained by bainite would be beneficial to increasing the work hardening rate.The optimum proportion of ferrite will result both higher stress ratio and uniform elongation in multi-phase steel.
