Unusual Effect of Oxygen on the Mechanical Behavior of a β-Type Titanium Alloy Developed for Biomedical Applications

2012 ◽  
Vol 706-709 ◽  
pp. 135-142 ◽  
Author(s):  
Mitsuo Niinomi ◽  
Masaaki Nakai
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Mechanical Behavior ◽  
Titanium Alloys ◽  
Biomedical Applications ◽  
The Other ◽  
Excess Oxygen ◽  
Ω Phase ◽  
Other Hand ◽  
Effect Of Oxygen

Oxygen enhances the strength of titanium alloys in general; however, excess oxygen can make titanium alloys brittle. On the other hand, oxygen enhances the precipitation of the α phase and suppresses the formation of the ω phase. Thus, using the optimal amount of oxygen is important to improve the mechanical properties of titanium alloys. The role of oxygen in titanium alloys is still not well understood. The effect of oxygen on the mechanical behavior of a β-type titanium alloy, Ti-29Nb-13Ta-4.6Zr (referred to as TNTZ), which is used for biomedical applications, was investigated in this study. Oxygen was found to stabilize the ω phase in TNTZ. This behavior of oxygen is unusual considering the known behavior of oxygen in titanium alloys: oxygen is known to suppress the formation of the ω phase in titanium alloys. A small amount of oxygen increases the tensile strength but decreases the ductility of TNTZ. On the other hand, a large amount of oxygen, of around 0.7 mass%, increases both the tensile strength and the ductility of TNTZ. This phenomenon is unexpected.

Enhancement of Mechanical Biocompatibility of Titanium Alloys by Deformation-Induced Transformation

2016 ◽  
Vol 879 ◽  
pp. 125-130
Author(s):  
Mitsuo Niinomi
Keyword(s):  
Fracture Toughness ◽  
Titanium Alloy ◽  
Phase Transformation ◽  
Titanium Alloys ◽  
Biomedical Applications ◽  
Hard Tissue ◽  
Β Phase ◽  
Ω Phase ◽  
Increased Strength ◽  
Strength And Ductility

Metastable β-type titanium alloys are highly suitable for use as structural biomaterials applied to hard tissue, i.e., as cortical bone (hereafter, bone) replacing implants. However, their mechanical biocompatibitities, such as the Young’s modulus, strength and ductility balance, fatigue strength, resistance against fatigue crack propagation and fracture toughness, require improvenent for increased compatibility with bone. Through deformation, the metastable β-phase in a metastable β-type titanium alloy is transformed into various phases, such as α’ martensite, α” martensite, and ω-phases with exact phase depending by metastable β-phase stability. In addition, twinning is also induced by deformation. Deformation twinning effectively enhances the work hardening in the metastable β-type titanium alloy, leading to increased strength and ductility. This improvement is accompanied by with other deformation-induced transformations including the appearance of deformation-induced martensite and ω-phase transformation. The enhancement of the mechanical biocompatibility of various materials using the abovementioned deformation-induced transformation is described in this paper, for both newly developed metastable β-type Ti-Mo and Ti-Cr alloys for biomedical applications.

Effect of Specimen Geometry on the Predicted Mechanical Behavior of Polyethylene Pipe Material

2014 ◽  
Author(s):  
Tarek M. A. A. El-Bagory ◽  
Tawfeeq A. R. Alkanhal ◽  
Maher Y. A. Younan
Keyword(s):  
Mechanical Behavior ◽  
Longitudinal Direction ◽  
Primary Objective ◽  
The Other ◽  
Pipe Material ◽  
Ring Specimen ◽  
Design Data ◽  
Practical Applications ◽  
Other Hand ◽  
Gauge Section

The primary objective of the present paper is to depict the mechanical behavior of high density polyethylene, (HDPE), pipes under different loading conditions with different specimen geometries to provide the designer with reliable design data relevant to practical applications. Therefore, it is necessary to study the effect of strain rate, ring configuration, and grip or fixture type on the mechanical behavior of dumb-bell-shaped, (DBS), and ring specimens made from HDPE pipe material. DBS and ring specimens are cut from the pipe in longitudinally, and circumferential (transverse) direction respectively. On the other hand, the ring specimen configuration is classified into two types; full ring, (FR), and notched ring, (NR) (equal double notch from two sides of notched ring specimen) specimens according to ASTM D 2290-12 standard. Tensile tests are conducted on specimens cut out from the pipe with thickness 10 mm at different crosshead speeds (10–1000 mm/min), and ambient temperature, Ta = 20 °C to investigate the mechanical properties of DBS, and ring specimens. In the case of test specimens taken from longitudinal direction from the pipe a necking phenomenon before failure appears at different locations along the gauge section. On the other hand, the fracture of NR specimens occurs at one notched side. The results demonstrated that the NR specimen has higher yield stress than DBS, and FR specimens at all crosshead speeds. The present experimental work reveals that the crosshead speed has a significant effect on the mechanical behavior of both DBS, and ring specimens. The fixture type plays an important role in the mechanical behavior for both FR and NR specimens at all crosshead speeds.

Surface Effect in a Metastable β Ti-Nb-Sn Alloy

2021 ◽  
Vol 1035 ◽  
pp. 562-567
Author(s):  
Li Chun Qi ◽  
Wen Xiao Qu ◽  
Yong Qi Zhu ◽  
Qing Liu
Keyword(s):  
Titanium Alloys ◽  
Orientation Relationship ◽  
Surface Effect ◽  
Phase Region ◽  
Martensite Phase ◽  
The Other ◽  
Β Phase ◽  
Ω Phase

The phase compositions of surface and interior in Ti-32Nb-4Sn metastable b alloy were investigated. It was found that this alloy exhibits surface effect significantly different from the effects reported in Ti-10V-2Fe-3Al, Ti-22Nb-9Zr and the other titanium alloys. The surface of Ti-32Nb-4Sn specimen quenched from single b phase region was characterized by dominant b phase and a few of α″ and ω phase. While in the interior of the alloy, a large amount of α² martensite phase was observed in addition to b phase The orientation relationship between the α″ martensite and β phase is (110)β∥(002)α″, (020)β∥(022)α″ and [001]β∥[100]α″.

scholarly journals Recent Applications of Nanomaterials in Prosthodontics

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Wang ◽  
Susan Liao ◽  
Yuhe Zhu ◽  
Ming Liu ◽  
Qian Zhao ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Surface Hardness ◽  
Filler Loading ◽  
The Other ◽  
Research Progress ◽  
Polymerization Shrinkage ◽  
Other Hand ◽  
Micron Size

In recent years, lots of researches have been launched on nanomaterials for biomedical applications. It has been shown that the performances of many biomaterials used in prosthodontics have been significantly enhanced after their scales were reduced by nanotechnology, from micron-size into nanosize. On the other hand, many nanocomposites composed of nanomaterials and traditional metals, ceramics, resin, or other matrix materials have been widely used in prosthodontics because their properties, such as modulus elasticity, surface hardness, polymerization shrinkage, and filler loading, were significantly increased after the addition of the nanomaterials. In this paper, the latest research progress on the applications of nanometals, nanoceramic materials, nanoresin materials, and other nanomaterials in prosthodontics was reviewed, which not only gives a detailed description of the new related investigations, but also hopefully provides important elicitation for future researches in this field.

scholarly journals Pengaruh Penambahan Beeswax Sebagai Plasticizer Terhadap Karakteristik Fisik Edible Film Kitosan [The Effect of Using Beeswax as Plasticizer Against Physical Characteristics of Chitosan Edible Film]

2018 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Sabrina Dhimas Putri Nabila ◽  
Rahayu Kusdarwati ◽  
Agustono Agustono
Keyword(s):  
Tensile Strength ◽  
Human Body ◽  
Environmentally Friendly ◽  
Edible Films ◽  
Physical Characteristics ◽  
The Other ◽  
Edible Film ◽  
Percent Elongation ◽  
Other Hand

AbstrakEdible film kitosan merupakan kemasan primer biodegradable yang dapat dimakan berbentuk lapisan tipis dan transparan. Edible film kitosan bersifat rapuh dan kurang fleksibel sehingga perlu ditambahkan plasticizer beeswax. Beeswax atau lilin lebah bersifat ramah lingkungan dan tidak berbahaya bagi tubuh manusia. Tujuan penelitian ini adalah untuk mengetahui film berbahan dasar kitosan dengan beeswax sebagai plasticizer dapat dijadikan sebagai bahan pembuatan edible film serta mengetahui pengaruh penambahan plasticizer beeswax terhadap karakteristik fisik edible film kitosan. Penelitian menggunakan rancangan acak lengkap (RAL) dengan enam perlakuan dan empat ulangan. Perlakuan dalam penelitian ini adalah penambahan konsentrasi beeswax yang berbeda yakni 0%, 1%, 2%, 3%, 4%, dan 5%. Hasil penelitian menunjukkan bahwa kitosan dan plasticizer beeswax dapat dijadikan sebagai bahan pembuatan edible film. Beeswax sebagai plasticizer memberikan pengaruh terhadap karakteristik fisik edible film kitosan. Nilai ketebalan pada edible film yang terbentuk bekisar antara 0,012-0,36 mm, kuat tarik antara 13,72 - 47,53kgf/cm2 dan persen pemanjangan antara 3,34 – 7,44 %. Peningkatan konsentrasi plasticizer beeswax menurunkan kuat tarik namun di sisi lain dapat meningkatkan nilai ketebalan dan nilai persen pemanjangan. AbstractEdible film of chitosan is the primary packaging of edible-shaped that biodegradable, thin and transparent. Edible film of chitosan are brittle and less flexible so that needs to be added plasticizer beeswax. Beeswax or beeswax is environmentally friendly and not harmful to the human body. The purpose of this research is to determine the film made from chitosan with beeswax as the plasticizer can serve as the ingredient edible film and figure out the influence of the addition of the plasticizer beeswax against physical characteristics of chitosanedible film. The results showed that chitosan and plasticizer beeswax can be used as material for edible films. Beeswax give influence on the physical characteristics of the edible film. The value of the thickness on edible film between 0.012-0.36 mm, tensile strength between 13.72-47.53 kgf/cm2 and percent of elongation 3.34 – 7.44%. The increased concentration of plasticizer beeswax lose strong pull but on the other hand can increase the value of the thickness and percent elongation

Mechanical Behaviors of Ti-29Nb-13Ta-4.6Zr-XO for Biomedical Applications Subjected to Cold Working and Various Heat Treatments

2007 ◽  
Vol 561-565 ◽  
pp. 1471-1476
Author(s):  
Mitsuo Niinomi ◽  
Toshikazu Akahori ◽  
Masaaki Nakai ◽  
Hiroshi Ishikawa ◽  
Michiharu Ogawa
Keyword(s):  
Elastic Modulus ◽  
Oxygen Content ◽  
Biomedical Applications ◽  
Cold Working ◽  
Early Stage ◽  
Age Hardening ◽  
Mechanical Behaviors ◽  
Ω Phase ◽  
Α Phase ◽  
Effect Of Oxygen

The effect of oxygen content on aging behavior and invar characteristics of Ti-29Nb-13Ta-4.6Zr (TNTZ) were investigated. The age hardening of TNTZ aged at 573 K and 723 K is enhanced with the oxygen content. The ω phase precipitates and grows from early stage of aging in TNTZ regardless of the oxygen content when aged at 573 K. The lath-like shape α phase precipitated in TNTZ aged at 723 K increases in size with the oxygen content. The elastic modulus increases with the oxygen content and aging. The ω phase increase the elastic modulus to a greater extent than the increase due to the α phase. The tensile strength increases with the oxygen content and aging, while the elongation decreases. TNTZ with oxygen content of 0.1 mass% exhibits invar-like characteristics through severe cold working. A higher oxygen content suppresses the invar-like characteristics of TNTZ.

Temperature Effect on Microstructure and Mechanical Behavior of Ti-15V-3Cr-3Al-3Sn

2011 ◽  
Vol 217-218 ◽  
pp. 1277-1282
Author(s):  
Rong Tan Huang ◽  
Wen Han Chen ◽  
Lv Wen Tsay
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Tensile Test ◽  
Mechanical Behavior ◽  
Temperature Effect ◽  
Aging Temperature ◽  
Aging Treatment ◽  
Α Phase ◽  
Environment Temperature ◽  
Notched Tensile Strength

Ti-15V-3Cr-3Al-3Sn, β-phase titanium alloy, is subjected to study the temperature effects on microstructure and mechanical behavior by using different aging temperature (426 ∼ 600 oC) and high temperature (450oC) notched tensile test. It follows that the highest hardness of Ti-15V-3Cr-3Al-3Sn would be got up to 420 Hv after 426 oC aging. Afterward, the hardness is decreasing with increasing aging temperature. By means of microstructure analyses, it reveals that the narrow and intragranular α-phase precipitates with lamella-shape in the grains at 426 oC aging treatment caused the age hardening of the titanium alloy. Subsequently, the α-phase precipitates were coarsening with increasing the aging temperature and showed the thick morphologies distributed along grain boundaries, which results in overaging. In the notched tensile test at 450oC, the highest notched tensile strength (1160 MPa) is also obtained after 426oC aging treatment, and then decreasing with increasing aging temperature. Its mechanical behavior is different from the room temperature notched tensile test, which demonstrates the lowest notched tensile strength (813 MPa) after 426 oC aging treatment due to the notched embrittlement effect. According to microstructure study, it suggests that the environment temperature effect enhanced the toughness of the alloy and terminated the notched embrittlement effect resulted from the 426oC aging treatment.

Mechanical Behavior of Aged Ti-15V-3Cr-3Sn-3Al Alloy

2013 ◽  
Vol 378 ◽  
pp. 82-86
Author(s):  
Ying Kai Chou ◽  
Leu Wen Tsay ◽  
Ying Chiao Wang ◽  
Chun Chen
Keyword(s):  
Tensile Strength ◽  
Mechanical Behavior ◽  
Aging Treatment ◽  
The Other ◽  
Second Step ◽  
Minor Effect ◽  
One Step ◽  
Notched Tensile Strength ◽  
The One ◽  
A Minor

The effect of aging treatments on the mechanical behavior of Ti-15V-3Cr-3Sn-3Al (Ti153) alloy was evaluated in the present study. Properties of the two-step aged specimens were also compared with those of the one-step aged specimens. The second aging treatment, which was performed at 426o°C for 24 h, apparently raised the tensile strength at the expense of the notched tensile strength for the specimens previously aged at 426°C or below. On the other hand, the second-step aging had a minor effect on further hardening of the specimens prior to aging at 538°C and 593°C. In general, theJ-integral value (fracture toughness) had the same trend as that of the notch brittleness of the specimens. Overall, the specimens subjected to the two-step aging treatment did not show any advantage over the specimens subject to one-step aging treatment.

Effect of Size-Dependent Cavitation on Micro- to Macroscopic Mechanical Behavior of Rubber-Blended Polymer

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Isamu Riku ◽  
Koji Mimura ◽  
Yoshihiro Tomita
Keyword(s):  
Surface Tension ◽  
Plastic Deformation ◽  
Mechanical Behavior ◽  
Volumetric Strain ◽  
Critical Value ◽  
The Other ◽  
Size Dependent ◽  
Other Hand ◽  
Blended Polymer ◽  
Onset Of Cavitation

In rubber-blended polymer, the onset of cavitation in the particles relaxes the high triaxiality stress state and suppresses the onset of crazing in the polymer. As a result, large plastic deformation is substantially promoted compared with single-phase polymer. On the other hand, it is also well known that the onset of cavitation depends on the size of particle. To investigate the size dependence of cavitation behavior in the particle, a theoretical analysis is done employing a void model under plane strain condition, which takes into account the surface tension and the limiting stretch of the void. Continuously, to study the effect of the size-dependent cavitation on the micro- to macroscopic mechanical behavior of the blend, a computational model is proposed for the blend consisting of irregularly distributed heterogeneous particles containing the void with surface force. The results indicate that when the size of the particle decreases to a critical value that depends on both the initial shear modulus of particle and the surface tension on the surface of void, the increase of the critical stress for the onset of cavitation becomes remarkable and consequently, the onset of cavitation is eliminated. When the particle is embedded in polymer, the relation between average normal stress, which is acting on the interface of particle and matrix, and volumetric strain of particle shows dependence on the size of particle but no dependence on the triaxiality of macroscopic loading condition. For the blend consisting of particles smaller than the critical value, the onset of cavitation is eliminated in particles and as a result, the conformation of the shape of particle to the localized shear band in matrix becomes difficult and the shear deformation behavior tends to occur all over the matrix. Furthermore, in this case, the area of the maximum mean stress is confined to the area adjacent to the particle and the value of it increases almost linearly throughout the whole deformation process, which would lead to the onset of crazing in matrix. On the other hand, it is clarified that the onset of cavitation is predominant in the localized microscopic region containing heterogeneous particles and therefore, the plastic deformation is promoted in this region.

Design and Research on Mechanical Properities of New Type Low Modulus Biomedical Metastable β Titanium Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 1667-1672
Author(s):  
Shuang Jin Liu ◽  
Fen Fei Cai ◽  
Chun Xiang Cui ◽  
Xun Yao ◽  
Li Chen Zhao
Keyword(s):  
Tensile Strength ◽  
Titanium Alloy ◽  
Biomedical Applications ◽  
Design Method ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Test Results ◽  
Biomechanical Compatibility ◽  
Low Modulus ◽  
New Type

One new type metastable β-titanium-alloy for biomedical applications Ti-25Nb-2Mo-4Zr (wt %) with lower elastic modulus was designed based on the d-electron alloy design method and prepared in this study. The microstructure and basic mechanical properties of designed alloy were investigated in this paper. The test results show that the Yang’s modulus is 65GPa and the tensile strength is 863MPa of designed alloy after solution treatment at 700°C for 0.5 h; the Yang’s modulus is 68GPa and the tensile strength is 1032MPa for the designed alloy after aging treatment at 500°C for 2 h. The designed alloy with lower Yang’s modulus is expected to have good prospects for implant biomaterials for its excellent biomechanical compatibility.

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