Production and Characterization of Porous Titanium Applied in Biomaterial

2017 ◽  
Vol 899 ◽  
pp. 179-184 ◽  
Author(s):  
Pâmela Karina S. Bomfim ◽  
Israel A. Cruz ◽  
Cátia Fredericci ◽  
Maurício David Martins das Neves
Keyword(s):  
Average Pore Size ◽  
High Strength ◽  
Porous Titanium ◽  
Alpha Phase ◽  
High Reactivity ◽  
Tissue Growth ◽  
Bending Test ◽  
Average Pore ◽  
Three Point Bending ◽  
Relevant Fact

The development of materials with a porous titanium surface has been widely studied in the field of biomaterials due to the excellent biocompatibility, high corrosion resistance and combination of high strength with low density. Another relevant fact is that porosity allows bone tissue growth. However, the high reactivity in liquid state ends up hindering titanium fusion, so an alternative is the powder metallurgy (PM).The aim of this work was to produce porous titanium samples by conventional PM. Porous samples was characterized by porosity and microstructure (optical microscopy - OP and scanning electron microscopy SEM), crystaline phase (X-ray diffraction –XRD), mechanical properties (three point bending test) and cytotoxic test. The results showed the presence of alpha phase, a decrease in the elasticity modulus, increase in average pore size and samples exhibited no toxic effects.

scholarly journals Effects of microsilica content on microstructure and strength of lightweight castable refractories containing porous corundum-spinel aggregate

2009 ◽  
Vol 41 (3) ◽  
pp. 275-281 ◽  
Author(s):  
W. Yan ◽  
N. Li ◽  
B.Q. Han
Keyword(s):  
High Temperature ◽  
Liquid Phase ◽  
Average Pore Size ◽  
Mercury Porosimetry ◽  
High Strength ◽  
Apparent Porosity ◽  
Liquid Content ◽  
Average Pore ◽  
Crushing Strength ◽  
Liquid Sintering

High-strength, lightweight castable refractories based on spinel were prepared by introducing porous corundum-spinel aggregate and appropriate microsilica. The effects of microsilica content on microstructure and properties of lightweight castable refractories were investigated using SEM, XRD, mercury porosimetry measurements and FactSage thermochemical software. It's found that microsilica was almost dissolved into a liquid phase at high temperature, which promoted liquid sintering. With increasing microsilica content, the matrices became denser and average pore size of matrices increased, then apparent porosity decreased, crushing strength increased and content of liquid phase in castables at 1600?C increased. The appropriate microsilica content is 0.65 to 1.95 wt%, which reaches to a compromise among apparent porosity (33-38%), crushing strength (82-125MPa) and liquid content (1.80~4.97 wt%).

Investigation of Mechanical Properties of Nano Sized Clay/LDH Particle as Hybrid Nano Composite Material

2015 ◽  
Vol 766-767 ◽  
pp. 355-361
Author(s):  
S. Sivasaravanan ◽  
V.K. Bupesh Raja ◽  
S. Prabhu ◽  
S. Dineshkumar ◽  
Gokulaprasad
Keyword(s):  
Composite Material ◽  
Testing Machine ◽  
Weight Ratio ◽  
High Strength ◽  
Sem Analysis ◽  
Bending Test ◽  
Flexural Property ◽  
Weight Percentage ◽  
Three Point Bending ◽  
Sonication Technique

Usage of Hybrid nanocomposite materials provides a greater opportunity to replace the conventional materials due to their properties such as light weight and high strength to based on weight ratio. In this synergitic study, nanosized clay particle and layered double hydroxide particles are used. nanoclay and LDH particles were mixed on the bases of weight percentage (1wt% to 5wt%) by ultra sonication technique. The composite material was fabricated by one of the most common method known as hand lay-up technique. The composite materials was prepared in the form of plate with 4mm of thickness.The characterization of tensile and flexural property of the nanoclay, LDH and combination of both was analysis by tensile test using universal testing machine and three point bending test respectively. The tensile and three point bending test specimens were cut to size as per ASTM standard.The morphology of composite was studied using SEM analysis.

An Experimental Evaluation of Energy Absorption of TRIP Steel by Small Punch Test

2016 ◽  
Vol 725 ◽  
pp. 60-65
Author(s):  
Asuka Hayashi ◽  
Takeshi Iwamoto
Keyword(s):  
Energy Absorption ◽  
Trip Steel ◽  
Dynamic Condition ◽  
High Strength ◽  
High Energy ◽  
Bending Test ◽  
Absorption Characteristic ◽  
Small Punch ◽  
Three Point Bending ◽  
Punch Test

TRIP steel possesses high strength and excellent ductility. In addition, it is possible that TRIP steel indicates high energy absorption so that TRIP steel is expected to apply to automotive members. To design the members made of TRIP steel, it is important to clarify its energy absorption characteristic at various deformation rates. In the previous study, the energy absorption characteristic of TRIP steel is evaluated by J-integral under quasi-static to dynamic condition by using a thick specimen based on ASTM standard. However, by using such thick specimens, it is difficult to conduct the three-point bending test under impact condition because of high ductility in TRIP steel. A small punch (SP) test is the experimental method which can evaluate fracture parameters such as J-integral. By using a conventional use of small specimen in the SP test, it is possible to evaluate J-integral of TRIP steel under impact deformation. In this study, energy absorption characteristic of TRIP steel is investigated by SP test under different deflection rates. Then, the relationship between the values of J-integral obtained by previously conducted three-point bending test and the SP test of TRIP steel is discussed.

The Preparation of High-Strength and Micropore Lightweight Bauxite Aggregate by In Situ Polymerization and Decomposition

2011 ◽  
Vol 194-196 ◽  
pp. 2135-2139
Author(s):  
Yi Neng Fang ◽  
Hua Zhi Gu ◽  
Yun Sheng Fen ◽  
Lin Jun Wang ◽  
Yan Jing Li
Keyword(s):  
Phase Composition ◽  
Pore Size ◽  
Aluminium Hydroxide ◽  
Average Pore Size ◽  
High Strength ◽  
Organic Polymer ◽  
Low Grade ◽  
Pore Former ◽  
Average Pore

High-strength and micropore lightweight bauxite aggregate was fabricated by low grade raw bauxite powder, aluminium hydroxide powder and organic polymer (OP). OP was used as consolidator, binder and pore former and aluminium hydroxide was used as pore former. The influence of OP and aluminium hydroxide content on the property of the samples was studied. The phase composition and the microstructure of the sintered samples were characterized by XRD, SEM and the pore size distribution was measured by mercury porosimety. The results demonstrate that the bulk density of the samples decreases linearly and the apparent porosity of the samples increases gradually with the addition of OP. The lowest density reached 1.13g/cm3when adding 35% OP and 10% Al(OH)3. The average pore size is around 5μm, and increases with the addition of OP increased. The XRD showed the main phase of the sample is mullite and some little amount of corundum.

J Integral of Steel Fiber Reinforced High Strength Concrete

2012 ◽  
Vol 476-478 ◽  
pp. 1568-1571
Author(s):  
Ting Yi Zhang ◽  
Guang He Zheng ◽  
Ping Wang ◽  
Kai Zhang ◽  
Huai Sen Cai
Keyword(s):  
High Strength Concrete ◽  
Fiber Volume Fraction ◽  
Steel Fiber ◽  
Volume Fraction ◽  
High Strength ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Three Point Bending ◽  
Strength Concrete

Through the three-point bending test on the specimens of steel fiber reinforced high strength concrete (SFHSC), the effects of influencing factors including water-cement ratio (W/C) and the fiber volume fraction (ρf) upon the critical value(JC) of J integral were studied. The results show that the variation tendencies of JC are different under different factors. JC meets the linear statistical relation with W/C, ρf, respectively.

Novel Micro-CT Based 3-Dimentional Structural Analyses of Porous Biomaterials

2007 ◽  
Vol 330-332 ◽  
pp. 967-970 ◽  
Author(s):  
B. Otsuki ◽  
Mitsuru Takemoto ◽  
Shunsuke Fujibayashi ◽  
Masashi Neo ◽  
Tadashi Kokubo ◽  
...  
Keyword(s):  
Network Structure ◽  
Bone Ingrowth ◽  
Average Pore Size ◽  
Three Dimensional ◽  
Porous Titanium ◽  
Titanium Implants ◽  
Average Pore ◽  
Tissue Ingrowth ◽  
Porous Biomaterials

A porous structure comprises pores and pore throats with a complex three-dimensional network structure, and many investigators have described the relationship between average pore size and the amount of bone ingrowth. However, the influence of network structure or pore throats for tissue ingrowth has rarely been discussed. Bioactive porous titanium implants with 48% porosity were analyzed using specific algorithms for three-dimensional analysis of interconnectivity based on a micro focus X-ray computed tomography system. In vivo histological analysis was performed using the very same implants implanted into the femoral condyles of male rabbits for 6 weeks. This matching study revealed that more poorly differentiated pores tended to have narrow pore throats, especially in their shorter routes to the outside. Data obtained suggest that this sort of novel analysis is useful for evaluating bone and tissue ingrowth into porous biomaterials.

scholarly journals Effect of Transition Layer on Properties of Tungsten-Tantalum (W-Ta) Laminated Composite

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 558
Author(s):  
Zizhi Yan ◽  
Gaoyong Xu ◽  
Jinping Suo
Keyword(s):  
Transition Layer ◽  
Laminated Composites ◽  
Laminated Composite ◽  
High Strength ◽  
Fracture Morphology ◽  
Bending Test ◽  
Tensile Fracture ◽  
Transition Layers ◽  
Three Point Bending ◽  
Plasma Sintering

Tungsten has many attractive properties, but its brittleness limits its application. Our team has found that the brittleness of tungsten can be greatly improved by combining the brittle tungsten with tantalum. Furthermore, we found that if a suitable transition layer is added between tungsten and tantalum, the properties of the composite will be further improved. In this paper, we studied the effect of different transition layers on the properties of W-Ta laminated composite to explore a suitable transition layer, which can effectively improve the toughness of the composite and solve the problem of tungsten application. We have prepared four kinds of W-Ta laminated composites with Ni, Ti, Nb, and Mo as transition layers. Ta-W laminated composites were prepared by stacking layers with Ta, transition layer, W alternately and sintered by spark plasma sintering (SPS). The tensile and three-point bending tests were carried to compare the mechanical properties. The tensile fracture morphology and three-point bending crack distribution were observed by SEM. In addition, the diffusion of elements in the transition layer and the influence of element diffusion on the tungsten structure were also studied to clarify the toughening mechanism. The results show that Nb is a satisfying transition layer, which not only improves the strength of W-Ta laminated composite, but also improves the toughness. The tensile test of W/Nb/Ta laminated composite shows a typical plastic fracture mode with an elongation of 13%. Three-point bending test also shows high strength and good toughness. In addition, Voigt model was used to predict the elastic modulus of W-Ta laminated composites and compared with the experimental results.

scholarly journals EFFECT OF AGAR-KAOLIN INTERACTION IN GELCASTING MIXTURES ON FORMING OF ALUMINA MEMBRANE SUPPORT

2018 ◽  
Vol 80 (3-2) ◽  
Author(s):  
Kowit Lertwittayanon
Keyword(s):  
Optimum Condition ◽  
Relative Density ◽  
Pore Size ◽  
Rough Surface ◽  
Sintering Temperature ◽  
Average Pore Size ◽  
High Strength ◽  
Asymmetric Membrane ◽  
Alumina Membrane ◽  
Average Pore

Disc alumina membrane supports were formed through agar gelcasting method. The agar gelcasting was expected to be environmentally-friendly forming technique using simple equipment. Final agar amounts (0.25 – 0.75wt%) in gelcasting mixtures were varied to find the optimum condition of shaping and the desired microstructure of sintered supports. The gelcasting mixtures were prepared from non-reactive grade Al2O3 and porcelain at the ratio of 98.5:1.5 by weight. The porcelain addition allowed the membrane support to have high strength at lower sintering temperature. When the final agar amounts increased from 0.25 to 0.75wt%, the dried, gelcast supports tended to have rough surface and subsequently resulting in crack. TGA profiles confirmed that there was interaction between agar chains and kaolin particles on cooling the gelcast supports leading to different microstructures after sintering. The final agar amount of 0.5 wt% provided the highest porosity of 48.9% and the highest relative density of 61.5%. Additionally, the average pore size of 1.5 µm was obtained at the final agar amount of 0.5 wt% suitable for using as asymmetric membrane support or microfiltration membrane.   

Characterisation of Foamed Porous Alumina Tissue Scaffolds

2009 ◽  
Vol 4 ◽  
pp. 21-26 ◽  
Author(s):  
E. Soh ◽  
Andrew Ruys
Keyword(s):  
Porous Alumina ◽  
High Strength ◽  
Tissue Growth ◽  
Tissue Scaffolds ◽  
High Porosity ◽  
Average Pore ◽  
Tissue Scaffold ◽  
Pore Sizes ◽  
Functional Balance ◽  
Pore Properties

A porous tissue scaffold depends on its ability to provide functional balance between mechanical strength, pore properties and interconnectivity of pores. High porosity levels, typically greater than 90% and pore sizes above 100µm are required for tissue growth and fixation. Alumina is a stable and very strong bioceramic which, when doped with calcium and phosphate ions, can potentially combine bioactivity with high porosity and high strength. Highly porous alumina foams were synthesized through heat induced chemical breakdown of precursor salt solutions. Pore sizes achieved for foamed alumina with moderate mole fractions are generally larger than 100µm. Foamed alumina with mole fractions on the extreme high and low ends shows lower average pore sizes. Compressive strength of synthesized foams falls in the range of 100kPa to 230kPa, significantly higher than porous biodegradable polymer tissue scaffolds. The significance of this work is that scaffolds can be produced with the unique combination of high porosity, high strength and biocompatibility.

Inferences of Baking Time on Hydrogen Embrittlement for High Strength Steel Treated with Various Zinc Based Electroplating

2021 ◽  
Vol 1016 ◽  
pp. 156-161
Author(s):  
Makoto Hino ◽  
Shunsuke Mukai ◽  
Takehiro Shimada ◽  
Koki Okada ◽  
Keitaro Horikawa
Keyword(s):  
Hydrogen Embrittlement ◽  
High Strength Steel ◽  
High Strength ◽  
Film Structure ◽  
Bending Test ◽  
Hydrogen Incorporation ◽  
Three Point Bending ◽  
Vacancy Clusters ◽  
Hydrogen Vacancy ◽  
Zinc Nickel

The hydrogen embrittlement of SK85 high-strength steel sheets was evaluated using a three-point bending test. The effect of electroplating the metal with zinc-based coatings on hydrogen embrittlement was examined by baking treatment of differently electroplated steel specimens. After electroplating, all the specimens underwent hydrogen embrittlement, promoted by hydrogen incorporation into the metal frame, owing to the reduction of hydrogen ions during electroplating. The hydrogen embrittlement of both zinc-and zinc-SiO2-electroplated SK85 steel continued after baking for 24 hours at 473 K, but that of zinc-nickel-and zinc-nickel-SiO2-electroplated SK85 steel ceased. Furthermore, TDA revealed that the trapped hydrogen could be released from steel at approximately 473 K. However, after baking, hydrogen embrittlement did not completely disappear, and we suggest that the formation of hydrogen vacancy clusters also accounts for this fracture phenomenon. The hydrogen incorporated into steel during electroplating led to the formation of hydrogen vacancy clusters, which allowed the formation of embrittlement. However, zinc and zinc-SiO2 films were not permeable enough to release these voids; while the peculiar zinc–nickel and zinc-nickel-SiO2 film structure enabled the hydrogen vacancy clusters to diffuse from the substrate.

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