Micromechanics, microstrains, and modelling of alpha, alpha–beta, and metastable beta Ti alloys

2010 ◽  
Vol 45 (5) ◽  
pp. 337-350 ◽  
Author(s):  
S L Raghunathan ◽  
R J Talling ◽  
D Dye
Keyword(s):  
Ti Alloys ◽  
Alpha Beta ◽  
Metastable Beta

Eletrochemical Behavior of Hot Swaged and Aged Ti-12Mo-13Nb Alloy

2017 ◽  
Vol 899 ◽  
pp. 295-298
Author(s):  
Sinara Borborema Gabriel ◽  
Gabriel Feliciano Santos ◽  
Artur da Silva Siqueira de Novais ◽  
Raphaela Paciello de Souza Lamarca ◽  
Carlos Angelo Nunes ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Biomedical Applications ◽  
Orthopedic Implants ◽  
Nacl Solution ◽  
Good Corrosion Resistance ◽  
Ti Alloys ◽  
Transmission Electron ◽  
Low Modulus ◽  
Potential Alternative ◽  
Metastable Beta

Recent studies have focused on the development of metastable beta-type Ti alloys with non-toxic elements such as Nb, Ta, Mo and Zr for biomedical applications. These alloys present low modulus, good mechanical compatibility and good corrosion resistance. Moreover, the processing variables can be controlled to produce microstructures with specific properties. In this regard, the objective of this work was to analyze the electrochemical behavior of Ti-13Nb-12Mo alloy hot forged and aged at 500 °C/24 h. The microstructure was analyzed by transmission electron microscopy. The corrosion tests were carried out under a NaCl solution at a temperature of 25 °C. The results showed that under the conditions studied Ti-12Mo-13Nb alloy exhibited passivation, which is desirable for corrosion resistance. Therefore the alloy is a potential alternative for the of Ti-6Al-4V used in orthopedic implants.

Phase transformation of metastable beta Ti alloys with tweed structure

2005 ◽  
Vol 11 (5) ◽  
pp. 365-369 ◽  
Author(s):  
Byung-Hak Choe ◽  
Soo-Keun Shin ◽  
Yeong Ouk Kim ◽  
Yong-Teak Hyun ◽  
Seung-Eon Kim ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Ti Alloys ◽  
Tweed Structure ◽  
Metastable Beta

scholarly journals The Role of Stress Induced Martensite in Ductile Metastable Beta Ti-alloys Showing Combined TRIP/TWIP Effects

2015 ◽  
Vol 2 ◽  
pp. S505-S510 ◽  
Author(s):  
F. Sun ◽  
J.Y. Zhang ◽  
C. Brozek ◽  
M. Marteleur ◽  
M. Veron ◽  
...  
Keyword(s):  
Ti Alloys ◽  
Metastable Beta

Change in Mechanical Strength and Bone Contact Ratio of Beta-Type TNTZ Subjected to Mechanical Surface Modification

2016 ◽  
Vol 879 ◽  
pp. 2371-2376
Author(s):  
Toshikazu Akahori ◽  
Tomokazu Hattori ◽  
Hisao Fukui ◽  
Mitsuo Niinomi
Keyword(s):  
Young’S Modulus ◽  
Vickers Hardness ◽  
Fine Particles ◽  
Young's Modulus ◽  
Solution Treatment ◽  
Contact Ratio ◽  
Bone Contact ◽  
Ti Alloys ◽  
Metastable Beta ◽  
Mechanical Surface

Ti-29Nb-13Ta-4.6Zr (TNTZ), which is one of metastable beta-type Ti alloys, has developed as one of representative biomedical and dental Ti alloys in Japan. TNTZ subjected to solution treatment shows Young’s modulus of 60 GPa, which is close to that of cortical bone. In addition, TNTZ has very low cytotoxicity and good bone biocompatibility as well. Heat treatment like solution treatment and aging (STA) is mainly used for improving the mechanical properties of metastable beta-type Ti alloys because of alpha precipitates, while Young’s modulus also rises drastically. This study was investigated the effects of mechanical surface modifications such as fine particle bombarding (FPB) with steel and hydroxyapatite particles or friction stir processing (FSP) on the mechanical strength of TNTZ in order to maintain low Young’s modulus. The relative bone contact ratios between the cancellous bones of Japanese white rabbits and column-shaped TNTZ subjected to FPB of steel particles were also evaluated. Vickers hardness (HV) of TNTZ subjected to FPB with fine particles of steel and hydroxyapatite particles increased by HV30 to 200 at the edge of the specimen surface to around 100 to 300 mm in depth as compared with that of TNTZ subjected to solution treatment. The hydroxyapatite layer was formed on the specimen surface by FPB with fine particles of hydroxyapatite particles, although the trend was not significant by FPB with steel particles. Furthermore, the fatigue strength in high cycle fatigue region of TNTZ subjected to FPB with steel particles was improved and the fatigue limit showed around 400 MPa, although that of TNTZ subjected to FPB with fine particles of hydroxyapatite particles were around 60 MPa higher than that to TNTZ subjected to solution treatment (230 MPa). TNTZ with a rough surface texture (Ra: 0.65 μm) showed a relative bone contact ratio of more than 80% after undergoing FPB with fine particles of steel particles; this value was significantly higher than that of TNTZ with a surface texture (Ra: 0.07 μm). Lastly, the microstructure of TNTZ subjected to FSP showed the recrystallization area by the frictional heating with very fine equiaxed beta phase with an average grain diameter of 3.0 μm. The change in Vickers hardness of TNTZ subjected to FSP was almost identical to that of Young’s modulus and showed the almost same trend of FPB.

Evolution of Microstructure and Microhardness in Ti-15Mo β-Ti Alloy Prepared by High Pressure Torsion

2016 ◽  
Vol 879 ◽  
pp. 2555-2560 ◽  
Author(s):  
Kristína Václavová ◽  
Josef Stráský ◽  
Jozef Veselý ◽  
Svetlana Gatina ◽  
Veronika Polyakova ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
High Pressure ◽  
Dislocation Density ◽  
Severe Plastic Deformation ◽  
High Pressure Torsion ◽  
Positron Annihilation Spectroscopy ◽  
Equivalent Strain ◽  
Ti Alloys ◽  
Evolution Of Microstructure ◽  
Metastable Beta

The main aim of this study is to analyze the effect of the severe plastic deformation (SPD) on the mechanical properties and defect structure of metastable beta Ti alloys. Experiments were performed on two different β-Ti alloys: Ti-15Mo and Ti-6.8Mo-4.5Fe-1.5Al which were subjected to severe plastic deformation (SPD) by high pressure torsion (HPT). The increase of hardness with increasing equivalent strain was determined by microhardness mapping. Dislocation density was studied by advanced techniques of positron annihilation spectroscopy (PAS). Microhardness and dislocation density increases with increasing equivalent strain inserted by severe plastic deformation.

scholarly journals Impacts of Machining and Heat Treating Practices on Residual Stresses in Alpha-Beta Titanium Alloys

2019 ◽  
Author(s):  
Lesley D. Frame ◽  
Indranie Rambarran ◽  
Kevin Sala ◽  
Cameron Sanders
Keyword(s):  
Residual Stresses ◽  
Thermal Processing ◽  
High Speed ◽  
Microstructural Characterization ◽  
Heat Treating ◽  
Cnc Machining ◽  
Ti Alloys ◽  
Beta Titanium ◽  
Stress Relieving ◽  
Alpha Beta

Abstract Machining and thermal processing can introduce undesirable residual stresses and distortion in titanium alloy components, and although the distribution and magnitude of these residual stresses is highly relevant for component and process design in the aerospace industry, the relationships between processing variables, processing steps, residual stress signature, and subsurface microstructures are not well understood. The current study reports on the preliminary results of experiments designed to mimic typical machining and thermal processing practices for aerospace alpha-beta Ti alloys. Traditional climb cutting and high-speed peel cutting operations are included in CNC machining experiments, and both stress-relieving and aging heat treatments are considered for thermal processing experiments. Characterization of samples includes strain measurement using the sin2ψ method with X-Ray Diffraction as well as microstructural characterization using traditional metallographic techniques. The results of this study point to potential areas for improving tool approach in machining practices for α-β Ti alloys.

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