scholarly journals SILVER ADDITIONS INFLUENCE ON BIOMEDICAL POROUS TI-NI SMAS FABRICATED BY MICROWAVE SINTERING

2018 ◽  
Vol 80 (4) ◽  
Author(s):  
Mustafa K. Ibrahim ◽  
Esah Hamzah ◽  
Safaa N. Saud ◽  
E. M. Nazim ◽  
Abdollah Bahador
Keyword(s):  
Elastic Modulus ◽  
Biomedical Applications ◽  
Microwave Sintering ◽  
Compressive Strain ◽  
X Ray Diffraction ◽  
X Ray ◽  
Porous Ti ◽  
Compression Strain ◽  
Silver Additions ◽  
Sintering Method

Ti-Ni and Ti-Ni-Ag shape memory alloys (SMAs) were prepared by microwave sintering. In Ti (49 -%Ag)-Ni51-Ag (atomic percentage), the silver was added with three percentages of (0.246, 0.5 and 1.51) at. %, respectively. The influence of Ag addition on the microstructure, phase composition, transformation temperatures and mechanical properties were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimeter (DSC) and compression test. The microstructure shows needles and plates inside Ti-rich region. The R phase appears at the plane (-112) and the plane (300). This phase has appeared during cooling and heating of the baseline of DSC test. The compression strain at maximum strength was improved, while the compression strength was reduced. The highest compressive strain was for the sample with 0.246 at. % Ag. The elastic modulus decreases with the increasing of Ag content. The elastic modulus of these alloys was low that make it proper for biomedical applications such as natural human bone due to the sintering method and also improve by adding silver. 

Formation of Tricalcium Silicate Prepared by Electric and Microwave Sintering

2010 ◽  
Vol 148-149 ◽  
pp. 1119-1123
Author(s):  
Kai Ke ◽  
Bao Guo Ma ◽  
Xiao Liang Wang ◽  
Xiang Guo Li
Keyword(s):  
Heating Temperature ◽  
Microwave Sintering ◽  
Electric Heating ◽  
Tricalcium Silicate ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Conventional Sintering ◽  
Sintering Method

A microwave sintering method was used to prepare C3S from Ca(OH)2, SiO2 and MexOy. f-CaO assay, X-ray diffraction and SEM were used to characterize the sintered samples.The results indicated that ion oxides played a very important role in C3S formation in conventional sintering, the use of MexOy as an additive was so effective in promoting C3S formation. The experimental results showed that samples were heated at an electric heating temperature(1500°C) and then further sintered with microwave for 30~60 min, tricalcium silicate could be formed with kilogram step. The new burning technique can greatly increase the forming speed of tricalcium silicate, MnO2, CuO and Ni2O3 could enhance the microwave sintering.

Fabrication of Ti-Based Biodegradable Material Composites Prepared by Spark Plasma Sintering Method

2010 ◽  
Vol 654-656 ◽  
pp. 2158-2161 ◽  
Author(s):  
Eri Miura-Fujiwara ◽  
Takeshi Teramoto ◽  
Hisashi Sato ◽  
Equo Kobayashi ◽  
Yoshimi Watanabe
Keyword(s):  
Spark Plasma Sintering ◽  
Sintering Temperature ◽  
Holding Time ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Porous Ti ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Sintering Method

This study aims at producing porous Ti filled with biodegradable materials for biomedical implants by means of spark plasma sintering method (SPS). To improve bone fixation and to obtain appropriate Young’s modulus as a medical implant material, we applied -tri calcium phosphate (-TCP) to the Ti-based composite. Ti/-TCP powder mixtures were sintered by SPS under applied stress of 45MPa with various temperatures and holding time. Vickers hardness (Hv) of obtained composite increased with increasing the holding time up to 10 min, and saturated hardness was approximately 750 Hv, which is extremely higher than that of bulk Ti. Hardness also increased as sintering temperature increased up to 1473 K. From the results of microstructure observations by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDXS), O- and P- containing Ti surrounded around Ti particle, and O diffused into Ti particle to a certain extent. X-ray diffraction results indicated several kinds of Ti-O and/or Ti-P formed in the specimen. Results indicated that it is the brittle phases formed during sintering that increased the hardness.

SYNTHESIS OF NANOCRYSTALLINE YIG USING MICROWAVE-HYDROTHERMAL METHOD

2009 ◽  
Vol 23 (17) ◽  
pp. 3637-3642 ◽  
Author(s):  
K. SADHANA ◽  
R. S. SHINDE ◽  
S. R. MURTHY
Keyword(s):  
Sintering Temperature ◽  
Microwave Sintering ◽  
Complex Permeability ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Hydrothermal ◽  
Transmission Electron ◽  
Dielectric Constant And Loss ◽  
Iron Garnet ◽  
Sintering Method

The aim of present research is to study the influence of sintering temperature on the preparation of nanocrystalline Yttrium Iron garnet (YIG) with improved magnetic properties. The nanocrystalline YIG powders were synthesized using Microwave-Hydrothermal (M-H) method. The synthesized powders were characterized using X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). The powders were sintered at various temperatures using microwave sintering method. The sintered samples were characterized using XRD. The complex permeability, dielectric constant and loss tangent of sintered YIG ceramic were also measured and discussed in this paper

Mesenchymal Stem Cell Response to Surface Altered Porous Ti

2015 ◽  
Vol 638 ◽  
pp. 67-72
Author(s):  
Ana Maria Salantiu ◽  
Florin Popa ◽  
Petru Pascuta ◽  
Olga Soritau ◽  
Noemi Dirzu ◽  
...  
Keyword(s):  
Stem Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemically Modified ◽  
Porous Ti ◽  
Average Porosity ◽  
Ft Ir ◽  
Cell Testing ◽  
Scanning Electron

This work aims to investigate the influence of surface conditioning of porous Ti for enhancing its biological activity, as assessed by in vitro stem cell testing. Porous Ti samples with an average porosity of 32% were processed by Powder Metallurgy with dextrin as a space holder. The samples were subjected to H2O2 treatment to form an enhanced TiO2 film, followed by a heat treatment at 400°C and 600°C aiming to the crystallization of the as-formed amorphous titanium oxide. Samples characterization was performed by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-Ray Diffraction (XRD). The treated surfaces revealed to be made of both anatase and rutile TiO2, with groove–shaped structure and cracks on the surface of the TiO2 film. The intrinsic biocompatibility of the chemically modified porous Ti surfaces was assessed in vitro. In our cell culture tests, stem cells were found to attach and proliferate better on the chemically treated Ti surfaces compared to the control untreated Ti surfaces.

Preparation and Research on the Lateral Elastic Modulus of the MnO2 Nanowires

2013 ◽  
Vol 662 ◽  
pp. 84-87
Author(s):  
Yong Jiang ◽  
Jian Cheng Deng ◽  
Yan Huai Ding ◽  
Jiu Ren Yin ◽  
Ping Zhang
Keyword(s):  
Elastic Modulus ◽  
Crystal Form ◽  
Bending Test ◽  
X Ray Diffraction ◽  
Nanowire Diameter ◽  
X Ray ◽  
Three Point Bending ◽  
Force Microscopy ◽  
Atomic Force ◽  
Mno2 Nanowires

MnO2 nanowires with large aspect ratio were successfully synthesized via a hydrothermal method. In this method, Mn(NO3)2 was as a source of manganese and NH4NO3 as an oxidant. The structure and morphology of the MnO2 nanowires were characterized by X ray diffraction (XRD) and scanning electron microscope (SEM). Their lateral elastic modulus was characterized via a nanoscale three-point bending test by atomic force microscopy (AFM) equipped with picoforce. The results indicate that the crystal form of MnO2 was β-MnO2. The elastic modulus of the nanowires decreased with the increase in nanowire diameter. This elastic modulus was in the range of 33.36-77.84GPa as the diameter ranged from 240 to 185nm.

Microwave Sintering of YSZ Electrolyte Materials for SOFC

2008 ◽  
Vol 368-372 ◽  
pp. 238-240 ◽  
Author(s):  
Xi Tang Wang ◽  
Girish M. Kale
Keyword(s):  
Microwave Sintering ◽  
X Ray Diffraction ◽  
Final Phase ◽  
X Ray ◽  
Microwave Furnace ◽  
Scanning Electron Microcopy ◽  
Conventional Sintering ◽  
Y2o3 Content ◽  
Ysz Electrolyte ◽  
Considerable Enhancement

Microwave sintering behaviors of four different compositions of YSZ electrolyte materials were investigated. The samples were sintered in 2.45GHz microwave furnace. For comparison, conventional sintering was performed at 1821K.The densities of sintered samples showed considerable enhancement in the densification process under the influence of microwave fields. The samples with lower Y2O3 content are easy to sinter. The influence of the composition and sintering methods on the final phase composition and microstructure were investigated by X-ray diffraction and scanning electron microcopy. Finer and more uniform microstructures were observed in the microwave sintered samples comparing to the conventionally sintered samples.

scholarly journals STARCH MEDIATED SYNTHESIS OF HYDROXYAPATITE NANOPARTICLE FOR BIOMEDICAL APPLICATIONS

2015 ◽  
Vol 2 (1) ◽  
pp. 15-17
Author(s):  
Indira J
Keyword(s):  
Biomedical Applications ◽  
Soluble Starch ◽  
Morphological Properties ◽  
Spherical Nanoparticles ◽  
Hydroxyapatite Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Average Size ◽  
Controllable Size

Hydroxyapatite (HAP) nanoparticles with uniform morphologies and controllable size have been synthesized by template directed method. The environment and eco-friendly polysaccharide soluble starch is used as a template to regulate size and shape of the nanoparticles synthesized. Structural and morphological properties of as-synthesized hydroxyapatite nanoparticles have been examined through the techniques like Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD) and Scanning Electron Microscopy(SEM), respectively. The results indicate that the obtained particles are uniform discrete spherical nanoparticles. The average size of the hydroxyapatite nanoparticles were ranged from 45 to 60 nm.

scholarly journals Iterative regularity and parent-offspring growth mold of stable grain array in bismuth silicate micro-crystals

2011 ◽  
Vol 43 (1) ◽  
pp. 105-112
Author(s):  
Z.G. Zhang ◽  
X.F. Wang ◽  
Q.Q. Tian
Keyword(s):  
Environmental Scanning Electron Microscopy ◽  
Morphological Properties ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Bismuth Silicate ◽  
X Ray ◽  
Offspring Growth ◽  
Line Spacing ◽  
Array Structure ◽  
Sintering Method

Bismuth silicate micro-crystals with grain array structure were prepared by sintering method under atmosphere pressure. The samples were characterized for structural and surface morphological properties by X-ray diffraction (XRD) and Environmental scanning electron microscopy (ESEM). The result shows that stable grain arrays grow by iterative mode. If a stable grain array eliminates, a new stable grain array will generate. In a stable parent array, an offspring array may generate after the corresponding partial elimination of its parent array. If one part of an offspring array stops growing, it will be as a new parent array, and then its offspring grain array will create. The sum of the lengths of an offspring array and the corresponding eliminated part of its parent array is equal to the length of the next eliminated part of its parent array. It means the growth rate of an offspring array is equal to that of the corresponding survived part of its parent array. There is a highly correlation between grain array length and average grain line spacing. It means that larger average grain line spacing corresponds to the stable grain array with lager length. When average grain line spacing increases 1?m, the corresponding array length will increase approximately 7.6?m.

Preparation and Microstructure of Pressureless Sintered Si2ON2-SiC Ceramic

2011 ◽  
Vol 335-336 ◽  
pp. 699-703
Author(s):  
Hui Hui Tan ◽  
Zhu Xing Tang ◽  
Xia Zhao ◽  
He Zhang
Keyword(s):  
Bulk Density ◽  
Sintering Temperature ◽  
Pressureless Sintering ◽  
Nitriding Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effect Of Additives ◽  
Sic Ceramic ◽  
Sintering Method ◽  
Scanning Electron

This paper introduces Si2ON2-SiC ceramic fabricated by pressureless sintering method and studies the effect of additives, nitriding temperatures on bulk density, porosity, phase composition and microstructure. It is discovered that additives MgO, CeO2 can increase the densities of Si2ON2-SiC ceramic apparently, and MgO additive has a better effect than CeO2. Nitriding temperature also is an important factor. The bulk density of the specimen with MgO additive reaches maximum at 1.91 g/cm3 when sintered at 1450 °C, and the bulk density of specimen with CeO2 additive is 1.86 g/cm3 at the same condition while the bulk density of the specimen without additive is only 1.75 g/cSuperscript textm3. The X-ray diffraction and scanning electron microscopy of the specimens show that the amount of Si2ON2 increase with the sintering temperature increase. But when the temperature is higher than 1500 °C the Si2ON2 grains will decompose into Si3N4, and Si2ON2 will vanish at 1550 °C

Physicochemical properties of chitosan–magnetite nanocomposites obtained with different pH

2021 ◽  
pp. 096739112110384
Author(s):  
Christian Chapa González ◽  
Javier Ulises Navarro Arriaga ◽  
Perla Elvia García Casillas
Keyword(s):  
Zeta Potential ◽  
Physicochemical Properties ◽  
Biomedical Applications ◽  
Spherical Shape ◽  
Polymeric Coating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Coated Nanoparticles ◽  
Nanoparticle Surface ◽  
Magnetite Phase

The physicochemical properties of the nanoparticle surface determine the performance of nanocomposites in biomedical applications such as their biodistribution and pharmacokinetics. The physicochemical properties of chitosan, such as apparent charge density and solubility, are pH dependent. Similarly, Fe3O4 nanoparticles are susceptible to variations in their physicochemical properties due to changes in pH. In this work, we evaluated the physicochemical properties of chitosan–magnetite nanocomposites that were suspended at pH 7.0, 9.0, and 11.0 to determinate the effect on particle size, zeta potential, and mass percentage of the polymeric coating, in addition to the crystalline phase and magnetic properties of magnetite phase. X-ray diffraction results exposed that the present phase was magnetite with no other phases present and that the crystallite size was between 10.8 and 14.1 nm. Fourier transform infrared verified the chitosan functional groups in treated samples while the percentage of mass determined by TGA found to be nearly 9%. Scanning electron microscopy micrographs corroborated the spherical shape of the bare and chitosan-coated nanoparticles. Dynamic light scattering results showed that chitosan coating modifies the zeta potential, going from a potential of −11.8 mV for bare particles to −3.0 mV (pH 11). Besides, vibrating sample magnetometer measurements showed that coercivity remained very low, which is desirable in biomedical applications.

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