Study on Diopside Whiskers Precipitation Type Hydroxyapatite

1989 ◽  
Vol 175 ◽  
Author(s):  
Toru Nonami
Keyword(s):  
Fracture Toughness ◽  
Composite Material ◽  
Fracture Surface ◽  
Bending Strength ◽  
Artificial Bone ◽  
Mixed Powder ◽  
Composite Body ◽  
Biomedical Material ◽  
Sintered Composite ◽  
Precipitation Type

AbstractA biomedical material for use as artificial bone and dental root is provided which takes the form of a sintered composite body comprising a Hydroxyapatite(HAP) and diopside whisker. The mixed powder of HAP and diopside was heated to make this composite material. The sintering of HAP and the precipitation of diopside whisker were examined, to find a method of making them occur simultaneously. Also, diopside was added to HAP and sintering at 1200°C for 2hr. was done. As a result of these investigations, diopside whisker of aspect ratio 101˜15 was formed. Moreover the intermediate layer of CaO-SiO2-P2O5-MgO system was generated at the interface of HAP and whisker. The bending strength of this sintered body was 300MPa and fracture toughness was 3.2MPa ·m1/2. These values were higher by about 2times or 3times than those of matrix HAP respectively. The increase in bending strength was attributed to an increase in fracture toughness, caused by an increase in fracture surface energy.

scholarly journals Fabrication of TiN Particle-Dispersed Al2O3 Composites Utilizing High N2-Pressure SHS

2011 ◽  
Vol 13 (3-4) ◽  
pp. 115
Author(s):  
Ken Hirota ◽  
Hajime Yagura ◽  
Katsuya Takaoka ◽  
Masaki Kato
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Thermal Decomposition ◽  
High Pressure ◽  
Bending Strength ◽  
Hot Isostatic Pressing ◽  
Mixed Powder ◽  
Second Stage ◽  
Powder Compacts ◽  
Tin Content

<p>Fabrication of fine TiN particle-dispersed dense Al<sub>2</sub>O<sub>3</sub> composites with the compositions of Al<sub>2</sub>O<sub>3</sub>/TiN=100/0~90/10 vol% has been conducted from Al<sub>2</sub>O<sub>3</sub>/(Ti,TiN<sub>0.3</sub>) mixed powder compacts by capsule-free hot isostatic pressing (HIP) utilizing high-pressure N<sub>2</sub> SHS. Fine Ti powders (φ ~ 0.3 μm) with TiN<sub>0.3 </sub>phase were prepared by thermal decomposition of planetary ball-milled fine TiH<sub>2</sub> powders at 400°C (673 K) for 1 h in a vacuum, followed by heating in N<sub>2</sub> at 200 °C (473 K) for 2 h. The Al<sub>2</sub>O<sub>3</sub> powder compacts (relative densities of 57.2-57.8%) with homogeneously dispersed (Ti,TiN<sub>0.3</sub>) particles were prepared. The mixed powder compacts were hot isostatically pressed (HIPed) under the conditions of 1350°C (1623 K) at 7 MPa N<sub>2 </sub>for 1 h, followed by the heating at the same temperature for 2 h under 196 MPa-N<sub>2</sub>. At the first stage of heating [1350°C (1623K)/7MPa/1h], solid/gas reaction of SHS between (Ti,TiN<sub>0.3</sub>) and N<sub>2</sub> was introduced to form TiN and densification of the Al<sub>2</sub>O<sub>3</sub> powder compacts up to the relative density of 92-93% with closed pores was performed. And at the sequent second stage [1350 °C (1623K)/196MPa/2h], densification of the most of pre-sintered composites consisting of Al<sub>2</sub>O<sub>3</sub> and TiN reached higher relative densities than 98.5%. Dispersion of TiN particles (~φ 0.30 μm) in the composites suppressed the grain growth of Al<sub>2</sub>O<sub>3</sub> during HIP-sintering. Mechanical properties, such as bending strength (σ<sub>b</sub>), Vickers hardness (<em>H</em><sub>V</sub>), fracture toughness (<em>K</em><sub>1C</sub>), and electrical resistivity (ρ) of the composites were evaluated as a function of TiN content; the maximum values of σ<sub>b</sub>=640 MPa, <em>H</em><sub>V</sub>=19.5 GPa, and <em>K</em><sub>IC</sub>=4.5 MPa・m<sup>1/2 </sup>were obtained in the Al<sub>2</sub>O<sub>3</sub>/TiN=97/3~95/5 vol% composites. Among the composites, the lowest ρ value of 2.6×10<sup>3</sup> Ω・m was attained at Al<sub>2</sub>O<sub>3</sub>/TiN=90/10 vol% composite.</p>

scholarly journals Development of Al-SiC composite material from rice husk and its parametric assessment

2022 ◽  
Author(s):  
Madhusudan Baghel ◽  
C M Krishna ◽  
S. Suresh
Keyword(s):  
Fracture Toughness ◽  
Composite Material ◽  
Surface Area ◽  
Rice Husk ◽  
Bending Strength ◽  
Research Work ◽  
Stir Casting ◽  
Bet Surface Area ◽  
Cnc Milling ◽  
Sem Images

Abstract In this research work, the development of Al-SiC composite material from rice husk and its parametric assessment is done using a CNC milling machine. They are further surface characterized, and mechanical properties such as BET surface area, SEM-EDX, and XRD, fracture toughness, tensile, and bending strength are studied. The machinability of the components is investigated for selected values of input-output parameters. Three castings, each with different particulate reinforcement combinations, are made with aluminum alloy (6061) using the stir casting method. BET surface area of extracted silica and Al-SiC composite material was found 374 m2/g and 150 m2/g, respectively. From results of BET surface area revealed that silica obtained from rice husk is more heterogeneous with a large surface area. A heterogeneous surface with larger pores was found through SEM images. XRD diffraction peaks show changes of amorphous silica into crystallinity in the composite material. The results also indicate that fracture toughness is very good at low temperatures and good machinability on CNC milling machines makes it suitable for aerospace applications.

scholarly journals Preparation of Nano-Hydroxyapatite Coated Carbon Nanotube Reinforced Hydroxyapatite Composites

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 357 ◽  
Author(s):  
Xueni Zhao ◽  
Xueyan Chen ◽  
Li Zhang ◽  
Qingyao Liu ◽  
Yao Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Compact Bone ◽  
Preparation Process ◽  
Artificial Bone ◽  
Mixed Acid ◽  
Nucleation Sites ◽  
Practical Guidance ◽  
Coated Carbon

Uniform and dense nano-hydroxyapatite (nHA) coating with nanorod-shaped structure was fabricated on carbon nanotubes (CNTs) by combining electrodeposition with biomineralization. The CNTs with nHA coating (nHA–CNTs) were used as reinforcement to improve the mechanical properties of HA. Firstly, a mixed acid solution of nitric acid and sulfuric acid was used to treat CNTs (NS–CNTs). The dispersion of NS–CNTs was obviously improved, and O-containing functional groups were grafted on the surfaces of NS–CNTs by treatment. Then, calcium phosphate (CaP) was deposited on NS–CNTs by electrodeposition, and NS–CNTs were provided with numerous active nucleation sites for the next coating preparation process. Then nanorod-shaped HA crystals were obtained on the surfaces of NS–CNTs by biomineralization. Using the CNTs with nHA coating (nHA–CNTs) as reinforcement, HA-based composites reinforced with CNTs and nHA–CNTs (nHA–CNTs/HA) were fabricated by pressure-less process. Bending strength and fracture toughness of 1.0 wt % nHA–CNTs reinforced HA composites (HAnC1) reaches a maximum (30.77 MPa and 2.59 MPa), which increased by 26.94% and 7.02% compared with 1.0 wt % CNTs reinforced HA composites, respectively. Importantly, the fracture toughness of HAnC1 is within the range of that to compact bone. This work provides theoretical and practical guidance for preparing nHA coating on nanomaterials. It also contributes to the potential application of nHA–CNTs/HA composites for artificial bone implants.

Preparation and Mechanical Properties of HA/PHB Composites

2010 ◽  
Vol 105-106 ◽  
pp. 104-107 ◽  
Author(s):  
Zhi Qi Zhuo ◽  
Li Min Dong ◽  
Cheng Wang ◽  
Qing Feng Zan ◽  
Jie Mo Tian
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Composite Materials ◽  
Fracture Surface ◽  
Surface Treatment ◽  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Bending Strength ◽  
Silane Coupling ◽  
The Impact

This paper focuses on the influence on the mechanical properties of hydroxyapatite / poly-hydroxybutyrate (HA / PHB) composites by different HA contents, and the effect of Silane coupling agent on improving the interface of HA/PHB composite materials. The HA/PHB composites were prepared by ball milling, hot-pressing, the HA content were 0, 5, 10, 15, 20 and 30wt%, respectively. Silane coupling agent was used for HA surface treatment in HA/PHB composites to compare with not having HA surface treatment in HA/PHB composite materials. The impact strength and flexural strength of HA / PHB composites were tested, and the microstructure of the fracture surface was observed by SEM. The results showed that HA could enhance the bending strength of HA/PHB composites. With HA content increased, the bending strength increased first and then decreased, when the HA content was 10wt%, the maximum bending strength reached 32.74MPa, increased about 41% comparing with pure PHB. Silane coupling agent can improve the interface of HA / PHB, then enhance the mechanical strength. When the HA content was 15wt%, the maximum bending strength reached 46.6MPa, Increased about 56% comparing with the same proportion of untreated HA/PHB composite material, and about double comparing with pure PHB.

The Influence of Sintering Temperature on the Mechanical Properties and Microstructure of Carbon Nanotubes/Zirconia/Hydroxyapatite Biocomposites

2013 ◽  
Vol 423-426 ◽  
pp. 38-42
Author(s):  
Ai Min Li ◽  
Kang Ning Sun ◽  
Run Hua Fan
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
Fracture Surface ◽  
Bending Strength ◽  
Electronic Materials ◽  
Sintering Temperature ◽  
Testing Machine ◽  
Materials Testing ◽  
Hot Pressing Sintering

Carbon nanotubes/zirconia/hydroxyapatite biocomposites was prepared by hot-pressing sintering under Ar atmosphere. The influence of sintering temperature on the mechanical properties and microstructure of carbon nanotube/zirconia/hydroxyapatite biocomposites was studied. We tested the bending strength and fracture toughness by universal electronic materials testing machine. The component of the composites was tested by XRD. The fracture surface of the composites was observed by SEM. The results indicate that the bending strength and fracture toughness of the composites is lower when the sintering temperature is lower than 1200°C. The difference of bending strength and fracture toughness at 1200°C and 1300°C is little. The number of them has risen markedly than the low temperature which reached to189.2MPa and 1.8MPa·m-1/2 respectively. The composition of the composites is mainly of hydroxyapatite, zirconia, carbon nanotubes, and a small amount of calcium phosphate, which indicated that part of the hydroxyapatite has decomposed. SEM photographs show that the fracture surface of the composites sintered at 1200 °C and 1300 °C is ductile fracture status and has bigger density.

Preparation and Mechanical Properties of Nanocobalt Coated Al2O3-TiC Composites

2007 ◽  
Vol 334-335 ◽  
pp. 913-916 ◽  
Author(s):  
Yan Sheng Yin ◽  
Shou Gang Chen ◽  
Xue Ting Chang ◽  
Alan Kin Tak Lau
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Liquid Phase ◽  
Fracture Surface ◽  
Bending Strength ◽  
Liquid Phase Sintering ◽  
Sem Images ◽  
Coating Layers ◽  
Cobalt Coating ◽  
Refinement Effect

Al2O3-TiC composites were fabricated by hot-pressing Cobalt coated powders at low temperature through liquid phase sintering. Cobalt coating layers effectively hinder the growth of grain and harmful reaction between Al2O3 and TiC particles, which would improve the mechanical properties of Al2O3-TiC composites. The hardness decreases with the increase of Co content and the bending strength was enhanced to 782MPa owing to the grain refinement effect of Co phase. The fracture toughness, about 9.23 MPa.m1/2, was measured for the composites containing 3wt% Co sintered at 1550°C. SEM images of fracture surface show that the toughening effect should be attributed to the conversion of fracture mode caused by the Co phase.

Mechanical Properties of CaB6 Sintered Body

2005 ◽  
Vol 297-300 ◽  
pp. 2707-2712
Author(s):  
Guang Hui Min ◽  
Li Xia Yang ◽  
Hua Shun Yu ◽  
Jiande Han
Keyword(s):  
Fracture Toughness ◽  
Fracture Surface ◽  
Intergranular Fracture ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Fracture Morphology ◽  
Sintered Body ◽  
Full Density ◽  
Transgranular Fracture ◽  
Sintering Aid

In this paper, CaB6 sintered body was fabricated by hot-pressed sintering with/without nickel as a sintering aid. The microstructure and fracture morphology were observed by means of SEM. CaB6 polycrystalline hot-pressed at 2123K showed insufficient densification. Fracture surface revealed that the existence of pores and the poor grain boundaries made the occurrence of intergranular fracture. When 28wt% nickel was added, nearly full density was obtained, although the sintering temperature is 200K lower. Hardness, Bending strength and fracture toughness of polycrystalline CaB6 were measured. By adding the Ni in CaB6 matrix, the flexural strength and the fracture toughness were enhanced, and the ratio of transgranular to intergranular fracture type was increased notably. The fracture surface showed a transgranular fracture. The crack bridging, micro-cracking and crack deflecting were deemed as the contribution to the improved fracture toughness.

In Situ Preparation and Mechanical Properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 Composites

2014 ◽  
Vol 602-603 ◽  
pp. 438-442
Author(s):  
Lei Yu ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Linear Increase ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Microstructure

Fully dense (ZrB2+ZrC)/Zr3[Al (Si)]4C6 composites with ZrB2 content varying from 0 to 15 vol.% and fixed ZrC content of 10 vol.% were successfully prepared by in situ hot-pressing in Ar atmosphere using ZrH2, Al, Si, C and B4C as raw materials. With the increase of ZrB2 content, both the bending strength and fracture toughness of the composites increase and then decrease. The synergistic action of ZrB2 and ZrC as reinforcements shows significant strengthening and toughing effect to the Zr3[Al (Si)]4C6 matrix. The composite with 10 vol.% ZrB2 shows the optimal mechanical properties: 516 MPa for bending strength and 6.52 MPa·m1/2 for fracture toughness. With the increase of ZrB2 content, the Vickers hardness of the composites shows a near-linear increase from 15.3 GPa to 16.7 GPa. The strengthening and toughening effect can be ascribed to the unique mechanical properties of ZrB2 and ZrC reinforcements, the differences in coefficient of thermal expansion and modulus between them and Zr3[Al (Si)]4C6 matrix, fine grain strengthening and uniform microstructure derived by the in situ synthesis reaction.

Effects of TiN Content on Mechanical Properties and Microstructure of ATN Materials

2013 ◽  
Vol 589-590 ◽  
pp. 590-593 ◽  
Author(s):  
Min Wang ◽  
Jun Zhao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Hot Press ◽  
Hot Press Sintering ◽  
Tin Content

In order to investigate the effects of TiN content on Al2O3/TiN ceramic material (ATN), the ATN ceramic materials were prepared of TiN content in 30%, 40%, 50%, 60% in the condition of hot press sintering. The sintering temperature is 1700°C, the sintering press is 32MPa, and the holding time are 5min, 10min, 15min. The effects of TiN content on mechanical properties and microstructure of ATN ceramic materials were investigated by analyzing the bending strength, hardness, fracture toughness. The results show that ATN50 has the best mechanical property, its bending strength is 659.41MPa, vickers hardness is 13.79GPa, fracture toughness is 7.06MPa·m1/2. It is indicated that the TiN content has important effect on microstructure and mechanical properties of ATN ceramic materials.

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