Effect of Phase Stability on Some Physical and Mechanical Properties in β-Ti Single Crystal for Biomedical Applications

2014 ◽  
Vol 783-786 ◽  
pp. 1372-1376 ◽  
Author(s):  
Mitsuharu Todai ◽  
Pan Wang ◽  
Keisuke Fukunaga ◽  
Takayoshi Nakano
Keyword(s):  
Physical Properties ◽  
Single Crystal ◽  
Young’S Modulus ◽  
Phase Stability ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
Elastic Stiffness ◽  
Alloy Single Crystal ◽  
Β Phase ◽  
Ti Alloys

The electron-atom ratio (e/a) dependence of the appearance of the lattice modulation and physical properties in β-phase Ti-xNb alloys (x= 28, 30, 34 and 40) were investigated by using some physical properties measurements, compressive test and transmission electron microscope observations (TEM observations), focusing on the β-phase stability. The microstructure, physical properties, deformation mode depend on thee/aratio which is closely related to the β-phase stability in Ti-Nb alloys. Thee/aratio is defined by the average electrons per atom in free atom configuration. Athermal ω-phase is suppressed in Ti-30Nb alloy single crystal with lowe/aratio. The Ti-30Nb alloy single crystal also exhibits a lattice modulation and low Debye temperature. These results imply that the β-phase stability in β-phase Ti alloys decreases with decreasing thee/aratio and are related to the softening of elastic stiffness,c′. Consequently, a decrease in thee/aratio leads to the softening ofc′ and a significant reduction in modulus along the [100] direction in β-phase Ti alloys single crystal. In fact, the Young’s modulus along [100] of the Ti-15Mo-5Zr-3Al alloy (wt.%) single crystal with lowe/aratio exhibits as low as 45 GPa, which is comparable to that the human cortical bone. That is, controlling thee/aratio is an ultimate strategy to develop the future superior biocompatible implant materials with extremely low Young’s modulus and good deformability.

scholarly journals Effect of Zr Content on Phase Stability, Deformation Behavior, and Young’s Modulus in Ti–Nb–Zr Alloys

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 476 ◽  
Author(s):  
Kyong Min Kim ◽  
Hee Young Kim ◽  
Shuichi Miyazaki
Keyword(s):  
Martensitic Transformation ◽  
Young’S Modulus ◽  
Phase Stability ◽  
Deformation Behavior ◽  
Young's Modulus ◽  
Temperature Deformation ◽  
Research Attention ◽  
Β Phase ◽  
Ti Alloys ◽  
Zr Alloys

Ti alloys have attracted continuing research attention as promising biomaterials due to their superior corrosion resistance and biocompatibility and excellent mechanical properties. Metastable β-type Ti alloys also provide several unique properties such as low Young’s modulus, shape memory effect, and superelasticity. Such unique properties are predominantly attributed to the phase stability and reversible martensitic transformation. In this study, the effects of the Nb and Zr contents on phase constitution, transformation temperature, deformation behavior, and Young’s modulus were investigated. Ti–Nb and Ti–Nb–Zr alloys over a wide composition range, i.e., Ti–(18–40)Nb, Ti–(15–40)Nb–4Zr, Ti–(16–40)Nb–8Zr, Ti–(15–40)Nb–12Zr, Ti–(12–17)Nb–18Zr, were fabricated and their properties were characterized. The phase boundary between the β phase and the α′′ martensite phase was clarified. The lower limit content of Nb to suppress the martensitic transformation and to obtain a single β phase at room temperature decreased with increasing Zr content. The Ti–25Nb, Ti–22Nb–4Zr, Ti–19Nb–8Zr, Ti–17Nb–12Zr and Ti–14Nb–18Zr alloys exhibit the lowest Young’s modulus among Ti–Nb–Zr alloys with Zr content of 0, 4, 8, 12, and 18 at.%, respectively. Particularly, the Ti–14Nb–18Zr alloy exhibits a very low Young’s modulus less than 40 GPa. Correlation among alloy composition, phase stability, and Young’s modulus was discussed.

scholarly journals First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Salloom ◽  
S. A. Mantri ◽  
R. Banerjee ◽  
S. G. Srinivasan
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
First Principles ◽  
Young's Modulus ◽  
Group Vi ◽  
Group V ◽  
Β Phase ◽  
Ti Alloys ◽  
Ω Phase ◽  
Stabilizer Concentration

AbstractFor decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical β-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing β-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young’s modulus of ω-phase also decreased at larger concentration of β-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young’s modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young’s modulus of Ti–W and Ti–Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in β-phase, and indicate that alloying is a promising route to enhance the ω-phase’s ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.

Significant reduction in Young's modulus of Fe–Ga alloy single crystal by inverse magnetostrictive effect under tensile stress

2018 ◽  
Vol 124 (23) ◽  
pp. 233901 ◽  
Author(s):  
S. Fujieda ◽  
S. Asano ◽  
S. Hashi ◽  
K. Ishiyama ◽  
T. Fukuda ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Single Crystal ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Alloy Single Crystal

A METALLURGICAL OVERVIEW OF TI – BASED ALLOY IN BIOMEDICAL APPLICATIONS

2015 ◽  
Vol 76 (7) ◽  
Author(s):  
Nur Hidayatul Nadhirah Elmi Azham Shah ◽  
Mazyan Yahaya ◽  
Maheran Sulaiman ◽  
Muhammad Hussain Ismail
Keyword(s):  
Young’S Modulus ◽  
Biomedical Application ◽  
Young's Modulus ◽  
Stress Shielding ◽  
Young Modulus ◽  
Processing Technique ◽  
Shielding Effect ◽  
Β Phase ◽  
Ti Alloys ◽  
Α Phase

Titanium (Ti)-based alloys are prominently used in biomedical application. This review paper emphasizes on some of the important aspects of the Ti-alloys in terms of metallurgical aspects, manufacturing routes and biocompatibility. Two kinds of structure are reviewed namely dense and porous, both differs in terms of purpose and satisfies different needs. This advancement of materials and equipment helps to improve the quality of life for patients and alleviate their health problems. Metallic materials, mainly Ti-based alloys have been used commercially as bone implant owing to its promising mechanical properties, biocompatibility and bioactivity. The outmost important issue in manufacturing  of  this  alloy  is  the  impurity  contents,  specifically  oxygen  and  carbon  which contribute   to decreasing in material performance of the alloy attributed from the formation of unwanted  oxide compounds such as TiO2 and  TiC. Another issue is the mismatch value of the Young’s modulus between the metallic implant and bone that result in stress shielding effect.  The structure of Ti-based  alloy is  mainly comprised of α-phase, β-phase or a combination of  both that result in variation of Young’s modulus ranging from 45 -110 GPa. Compared to α-phase Ti alloy, the β-phase rich alloys may exhibit lower value of Young modulus through the right processing technique. Therefore, the development of β-phase Ti-alloys has been researched progressively in line with the need of low Young’s modulus that suit for implant applications.

Phase Stability and Mechanical Properties of Ti-Cr Based Alloys with Low Young’s Modulus

2010 ◽  
Vol 654-656 ◽  
pp. 2114-2117 ◽  
Author(s):  
Yonosuke Murayama ◽  
Shuichi Sasaki ◽  
Hisamichi Kimura ◽  
Akihiko Chiba
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Phase Stability ◽  
Deformation Mechanism ◽  
Young's Modulus ◽  
Deformation Behaviour ◽  
System Alloy ◽  
Β Phase ◽  
Ω Phase ◽  
Cr System

This work investigates the mechanical properties of Ti-Cr system alloys and focuses on the microstructure, the Young’s modulus, the deformation mechanism and the deformation behaviour observed in various alloy compositions. The addition of Al to the Ti-Cr system alloys greatly decreases the Young’s modulus. Addition of Al, Sn and Zr to various Ti-Cr alloys suppresses the athermal ω phase that forms during quenching from β field. A Ti-Cr system alloy with low Young’s modulus was obtained in suitable compositional combination of Cr, Zr and Sn or Al. The alloys with the composition where the quenched microstructure transits from martensite to meta-stable β phase show low Young’s modulus. In addition, the alloys show two-step yielding due to stress-induced transformation.

Investigation of the Influence of Ti-Nb Alloy Composition on the Structure of the Ingots Produced by Arc Melting

2015 ◽  
Vol 1085 ◽  
pp. 307-311 ◽  
Author(s):  
Yurii Sharkeev ◽  
Zhanna G. Kovalevskaya ◽  
Qi Fang Zhu ◽  
Margarita A. Khimich ◽  
Evgeniy A. Parilov
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Alloy Composition ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Β Phase ◽  
Arc Melting ◽  
Α Phase

The results of investigation of the structure, physical and mechanical properties of the Ti-Nb alloy ingots with different composition obtained by arc melting are presented. X-ray diffraction and microstructural analyses were used. Microhardness was measured and the Young’s modulus of the alloys was evaluated. When the content of niobium in the alloy changes from 10 to 40 mass.%, phase composition of the alloy varies from α-and α'-phase (10 mass.% of Nb) to α'-, α''- and β-phases (25 mass.% of Nb), to the β-phase (40 mass.% of Nb). The alloy containing 40 mass.% Nb has the lowest Young’s modulus.

Elastic constants of single crystal γ – TiAl

1995 ◽  
Vol 10 (5) ◽  
pp. 1187-1195 ◽  
Author(s):  
Y. He ◽  
R.B. Schwarz ◽  
A. Migliori ◽  
S.H. Whang
Keyword(s):  
Single Crystal ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Theoretical Calculations ◽  
Elastic Stiffness ◽  
Orientation Dependence ◽  
Polycrystalline Materials ◽  
Ultrasonic Spectroscopy ◽  
First Time ◽  
Good Agreement

The six independent second-order elastic stiffness coefficients of a Ti44Al56 single crystal (L10 structure) have been measured at room temperature for the first time using a resonant ultrasonic spectroscopy (RUS) technique. These data were used to calculate the orientation dependence of Young's modulus and the shear modulus. Young's modulus is found to reach a maximum near a [111] direction, close to the normal to the most densely packed planes. The elastic moduli and Poisson's ratio for polycrystalline materials, calculated by the averaging scheme proposed by Hill, are in good agreement with experimental data and theoretical calculations.

Development of the Snoek Anelastic Relaxation Correlated with Oxygen in β-Ti Alloys

2019 ◽  
Vol 298 ◽  
pp. 59-63 ◽  
Author(s):  
Zheng Cun Zhou ◽  
J. Du ◽  
S.Y. Gu ◽  
Y.J. Yan
Keyword(s):  
Internal Friction ◽  
Physical And Mechanical Properties ◽  
Peak Height ◽  
Relaxation Peak ◽  
Interstitial Oxygen ◽  
Internal Friction Peak ◽  
Β Phase ◽  
Ti Alloys ◽  
Interstitial Atoms ◽  
The Stability

The β-Ti alloys exhibit excellent shape memory effect and superelastic properties. The interstitial atoms in the alloys have important effect on their physical and mechanical properties. For the interstitial atoms, the internal friction technique can be used to detect their distributions and status in the alloys. The anelastic relaxation in β-Ti alloys is discussed in this paper. β-Ti alloys possesses bcc (body center body) structure. The oxygen (O) atoms in in the alloys is difficult to be removed. The O atoms located at the octahedral sites in the alloys will produce relaxation under cycle stress. In addition, the interaction between the interstitial atoms and substitute atoms, e.g., Nb-O,Ti-O can also produce relaxation. Therefore, the observed relaxational internal friction peak during the measuring of internal friction is widened. The widened multiple relaxation peak can be revolved into Debye,s elemental peaks in Ti-based alloys. The relaxation peak is associated with oxygen movements in lattices under the application of cycle stress and the interactions of oxygen-substitute atoms in metastable β phase (βM) phase for the water-cooled specimens and in the stable β (βS) phase for the as-sintered specimens. The damping peak height is not only associated with the interstitial oxygen, but also the stability and number of βM in the alloys.

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