First principles theoretical investigations of low Young's modulus beta Ti-Nb and Ti-Nb-Zr alloys compositions for biomedical applications.
High alloyed β-phase stabilized titanium alloys are known to provide comparable Young's modulus as that to the human bones (~30 GPa) but is marred by its high density. In the present study the low titanium alloyed compositions of binary Ti-Nb and ternary Ti-Nb-Zr alloy systems, having stable β-phase with low Young's modulus are identified using first principles density functional framework. The theoretical results suggest that the addition of Nb in Ti and Zr in Ti-Nb increases the stability of the β-phase. The β-phase in binary Ti-Nb alloys is found to be fully stabilized from 22 at.% of Nb onwards. The calculated Young's moduli of binary β-Ti-Nb alloy system are found to be lower than that of pure titanium (116 GPa). For Ti-25(at.%)Nb composition the calculated Young's modulus comes out to be ~80 GPa. In ternary Ti-Nb-Zr alloy system, the Young's modulus of Ti-25(at.%)Nb-6.25(at.%)Zr composition is calculated to be ~50 GPa. Furthermore, the directional Young's moduli of these two selected binary (Ti-25(at.%)Nb) and ternary alloy (Ti-25(at.%)Nb-6.25(at.%)Zr) compositions are found to be nearly isotropic in all crystallographic directions.
Dept. of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Yeddumailaram 502205, Telangana, India.
Rajamallu
R
Karre
Dept. of Physics, Indian Institute of Technology Hyderabad, Yeddumailaram 502205, Telangana, India.
Manish K
MK
Niranjan
Dept. of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Yeddumailaram 502205, Telangana, India. Electronic address: suhash@iith.ac.in.
Suhash R
SR
Dey
D000497:Alloys / Q000737:chemistry*; D016880:Anisotropy; D020811:Biomedical Technology / Q000379:methods*; D055119:Elastic Modulus; D006801:Humans; D033081:Shear Strength; D013816:Thermodynamics; D014025:Titanium / Q000737:chemistry*
D000497:Alloys; C090153:titanium alloy (TiNb13Zr13); C575293:titanium-niobium alloy; D014025:Titanium
Ab-initio calculations; Alloy design; Biomedical; Density functional theory; Elastic properties; Phase stability-prediction