scholarly journals Kinetics of Capability Aging in Ti-13Nb-13Zr Alloy

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 693 ◽  
Author(s):  
Myoungjae Lee ◽  
In-Su Kim ◽  
Young Hoon Moon ◽  
Hyun Sik Yoon ◽  
Chan Hee Park ◽  
...  

Metals for biomedical implant applications require a simultaneous achievement of high strength and low Young’s modulus from the viewpoints of mechanical properties. The American Society for Testing and Materials (ASTM) standards suggest two types of processing methods to confer such a mechanical performance to Ti-13Nb-13Zr alloy: solution treatment (ST) and capability aging (CA). This study elucidated the kinetics of CA process in Ti-13Nb-13Zr alloy. Microstructural evolution and mechanical change were investigated depending on the CA duration from 10 min to 6 h. The initial ST alloy possessed the full α′-martensitic structure, leading to a low strength, low Young’s modulus, and high ductility. Increasing CA duration increased mechanical strength and Young’s modulus in exchange for the reduction of ductility. Such a tendency is attributed to the decomposition of α′ martensite into (α+β) structure, particularly hard α precipitates. Mechanical compatibility (i.e., Young’s modulus compensated with a mechanical strength) of Ti-13Nb-13Zr alloy rarely increased by changing CA duration, suggestive of the intrinsic limit of static heat treatment.

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1491 ◽  
Author(s):  
Vasile Danut Cojocaru ◽  
Anna Nocivin ◽  
Corneliu Trisca-Rusu ◽  
Alexandru Dan ◽  
Raluca Irimescu ◽  
...  

The influence of complex thermo-mechanical processing (TMP) on the mechanical properties of a Ti-Nb-Zr-Fe-O bio-alloy was investigated in this study. The proposed TMP program involves a schema featuring a series of severe plastic deformation (SPD) and solution treatment (STs). The purpose of this study was to find the proper parameter combination for the applied TMP and thus enhance the mechanical strength and diminish the Young’s modulus. The proposed chemical composition of the studied β-type Ti-alloy was conceived from already-appreciated Ti-Nb-Ta-Zr alloys with high β-stability by replacing the expensive Ta with more accessible Fe and O. These chemical additions are expected to better enhance β-stability and thus avoid the generation of ω, α’, and α” during complex TMP, as well as allow for the processing of a single bcc β-phase with significant grain diminution, increased mechanical strength, and a low elasticity value/Young’s modulus. The proposed TMP program considers two research directions of TMP experiments. For comparisons using structural and mechanical perspectives, the two categories of the experimental samples were analyzed using SEM microscopy and a series of tensile tests. The comparison also included some already published results for similar alloys. The analysis revealed the advantages and disadvantages for all compared categories, with the conclusions highlighting that the studied alloys are suitable for expanding the database of possible β-Ti bio-alloys that could be used depending on the specific requirements of different biomedical implant applications.


2009 ◽  
Vol 618-619 ◽  
pp. 303-306 ◽  
Author(s):  
Zhen Tao Yu ◽  
Gui Wang ◽  
Xi Qun Ma ◽  
Matthew S. Dargusch ◽  
Jian Ye Han ◽  
...  

The effects of alloy chemistry and heat treatment on the microstructure and mechanical properties of Ti-Nb-Zr-Mo-Sn near  type titanium alloys have been investigated. Near β titanium alloys consisting of non-toxic alloying elements Mo, Nb, Zr, Sn possess a low Young’s modulus, and moderate strength and plasticity. As the hot rolled TLM alloy (Ti-25Nb-3Zr-3Mo-2Sn) possesses high strength and low Young’s modulus a detailed investigation is performed for this alloy. Solution treatment of the hot rolled TLM alloy reduces strength and increases ductility without affecting the Young’s modulus. Ageing of the solution treated TLM alloy reduces elongation and increases the Young’s modulus with little change in strength. Both solution treated and aged conditions show features of two stage yielding associated with a strain induced martensitic transformation.


2012 ◽  
Vol 472-475 ◽  
pp. 1813-1817 ◽  
Author(s):  
Yu Lin Yang ◽  
Zhe Yong Fan ◽  
Ning Wei ◽  
Yong Ping Zheng

In this paper the mechanical properties of a series of hydrogen functionalized graphyne are investigated through acting tensile loads on the monolayer networks. Molecular dynamics simulations are performed to calculate the fracture strains and corresponding maximum forces for pristine graphyne along both armchair and zigzag directions. Furthermore, hydrogen functionalized graphynes with different functionalization sites are analyzed to investigate the effect of functionlization on the mechanical performance. Finally, Young's modulus of all the investigated architectures are computed. The obtained results show that monolayer graphyne is mechanically stable with high strength and stiffness, and the mechanical performance can be tuned through structure engineering and functionalization.


2014 ◽  
Vol 783-786 ◽  
pp. 1215-1220
Author(s):  
Toshikazu Akahori ◽  
Yurie Oguchi ◽  
Tomokazu Hattori ◽  
Hisao Fukui ◽  
Mitsuo Niinomi

Beta-type Ti-29Nb-13Ta-4.6Zr (TNTZ) was recently developed as a representative biomedical Ti alloy. As-solutionized TNTZ has a low Young’s modulus less than 60 GPa close to that of cortical bone along with very low cytotoxicity and good bone biocompatibility. Solution treatment and aging (STA) is a typical heat treatment for improving the mechanical properties of beta-type titanium alloys. However, STA also drastically increases the Young’s modulus. Therefore, this study investigated the effects of surface modification, micro-shot peening, on the mechanical properties of TNTZ subjected to severe thermomechanical treatment in order to maintain a relatively low Young’s modulus. The bone contact characteristics of TNTZ samples subjected to surface modification and cancellous bone were also compared. The Vickers hardness of cold-swaged TNTZ (TNTZSW) subjected to micro-shot peening was significantly increased within 20 mm from the very edge of the specimen surface. The fatigue strength of TNTZSWsubjected to micro-shot peening increased especially in the high cycle fatigue life region. The fatigue limit was around 400 MPa. The bone formations on TNTZSWsubjected to micro-shot peening and TNTZSWwith the mirror surface as comparison material were almost identical to each other. However, the relative bone contact ratio of TNTZSWsubjected to micro-shot peening was better than that of TNTZSWwith the mirror surface.


2010 ◽  
Vol 638-642 ◽  
pp. 495-500 ◽  
Author(s):  
Toshikazu Akahori ◽  
Mitsuo Niinomi ◽  
Masaaki Nakai ◽  
Harumi Tsutsumi ◽  
Tomokazu Hattori ◽  
...  

A new -type Ti alloy composed of non-toxic and allergy-free elements like Nb, Ta, and Zr, Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) proposed by present authors, has been developed in order to achieve relatively low Young’s modulus and excellent mechanical performance. On the other hand, Zr has been also paid attention as metallic biomaterial for the next generation because of good biocompatibility nearly equal to Ti or a few GPa smaller Young’s modulus as compared to one. In this study, mechanical performances such as tensile properties and Young's modulus of TNTZ subjected to thermo-mechanical treatments or severe deformation, and the mechanical properties and biocompatibility of Zr-Nb system alloys were investigated in order to judge their potential for biomedical applications. Young’s modulus of as-solutionized TNTZ, which is around 63 GPa, is pretty similar to that of as-cold-rolled TNTZ. The Young’s moduli of hot-rolled Ti-6Al-4V ELI alloy are respective around 110 GPa. The Young’s moduli of as-solutionized and as-cold-rolled TNTZ are around a half of those, and are twice as large as that of the cortical bone. The tensile strengths of TNTZ aged after solution treatment and those aged after cold rolling decrease with an increase in the aging temperature, although the elongation shows the reverse trend. The tensile strength of as-cold-rolled TNTZ is improved drastically through severe deformation such as high pressure torsion and shows more than 1000 MPa. Zr-XNb system alloy (X: 5-30mass%) shows the smallest value of Young’s modulus (around 58 GPa) at Nb content of 20mass%. In the case of implantation of the bars made of Zr-XNb system alloys into the lateral femoral condyles of Japanese white rabbits, the tendency of contact between the cancellous bone and the bar becomes remarkably at 24 weeks after the implantation according to increasing with Nb content.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3467
Author(s):  
Anna Nocivin ◽  
Doina Raducanu ◽  
Bogdan Vasile ◽  
Corneliu Trisca-Rusu ◽  
Elisabeta Mirela Cojocaru ◽  
...  

The present paper analyzed the microstructural characteristics and the mechanical properties of a Ti–Nb–Zr–Fe–O alloy of β-Ti type obtained by combining severe plastic deformation (SPD), for which the total reduction was of etot = 90%, with two variants of super-transus solution treatment (ST). The objective was to obtain a low Young’s modulus with sufficient high strength in purpose to use the alloy as a biomaterial for orthopedic implants. The microstructure analysis was conducted through X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) investigations. The analyzed mechanical properties reveal promising values for yield strength (YS) and ultimate tensile strength (UTS) of about 770 and 1100 MPa, respectively, with a low value of Young’s modulus of about 48–49 GPa. The conclusion is that satisfactory mechanical properties for this type of alloy can be obtained if considering a proper combination of SPD + ST parameters and a suitable content of β-stabilizing alloying elements, especially the Zr/Nb ratio.


2021 ◽  
pp. 130308
Author(s):  
E.S.N. Lopes ◽  
L.U. dos Santos ◽  
R. Caram ◽  
K.N. Campo

Author(s):  
Fei Qin ◽  
Shuai Zhao ◽  
Yanwei Dai ◽  
Lingyun Liu ◽  
Tong An ◽  
...  

Abstract Thermo-mechanical reliability assessment for sintered silver is a crucial issue as sintered silver is a promising candidate of die-attachment materials for power devices. In this paper, the nano-indentation tests are performed for sintered silver in typical die-attach interconnection under different thermal cycles. Based on thermal cycling test, the Young's modulus and hardness of sintered silver layer have been presented. It is found that the Young's modulus and hardness of sintered silver layer changes slightly although the microstructure of sintered silver also presents some variations. The stress and strain curves for different thermal cycling tests for sintered silver based on reverse analysis of nano-indentation are also given. The results show that the elastoplastic constitutive equations change significantly after thermal cycling tests, and the yielding stress decreases remarkably after 70 thermal cycles. The experimental investigation also show that the cracking behaviors of sintered silver depends on its geometry characteristics, which implies that the possible optimization of sintered silver layer could enhance its thermo-mechanical performance.


2016 ◽  
Vol 22 (4) ◽  
pp. 841-844 ◽  
Author(s):  
Tye Langston

AbstractCarbon fibers exhibit exceptional properties such as high stiffness and specific strength, making them excellent reinforcements for composite materials. However, it is difficult to directly measure their tensile properties and estimates are often obtained by tensioning fiber bundles or composites. While these macro scale tests are informative for composite design, their results differ from that of direct testing of individual fibers. Furthermore, carbon filament strength also depends on other variables, including the test length, actual fiber diameter, and material flaw distribution. Single fiber tensile testing was performed on high-strength carbon fibers to determine the load and strain at failure. Scanning electron microscopy was also conducted to evaluate the fiber surface morphology and precisely measure each fiber’s diameter. Fiber strength was found to depend on the test gage length and in an effort to better understand the overall expected performance of these fibers at various lengths, statistical weak link scaling was performed. In addition, the true Young’s modulus was also determined by taking the system compliance into account. It was found that all properties (tensile strength, strain to failure, and Young’s modulus) matched very well with the manufacturers’ reported values at 20 mm gage lengths, but deviated significantly at other lengths.


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