Preparation and characterization of porous hydroxyapatite pellets: Effects of calcination and sintering on the porous structure and mechanical properties

2016 ◽  
Vol 230 (6) ◽  
pp. 985-993 ◽  
Author(s):  
Onder Albayrak ◽  
Mehmet Ipekoglu ◽  
Nazim Mahmutyazicioglu ◽  
Mehmet Varmis ◽  
Emrah Kaya ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Porous Structures ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
Porous Hydroxyapatite ◽  
Urea Content ◽  
Hydroxyapatite Powder ◽  
Density Values

In this study, porous hydroxyapatite structures were produced by using urea particles of 600–850 µm size. Samples with two different urea composition (25 and 50 wt%) were prepared along with samples without any urea content by adding urea to commercially available hydroxyapatite in its as purchased and calcined states. The produced pellets were sintered at 1100 ℃ and 1200 ℃ for 2 h. Compression tests and microhardness measurements were conducted and changes in density values were examined in order to determine the effect of the calcination state of the prior hydroxyapatite powder, the sintering temperature and the amount of urea added. Also X-ray diffraction, Fourier transform infrared, and scanning electron microscopy analyses were conducted to determine the phase stability, functional groups, and pore morphology, respectively. Calcination is found to negatively affect the densification and sinterability of the produced samples, resulting in a decrease of compressive strength and microhardness. With the control of the urea content and sintering temperature uncalcined hydroxyapatite can successfully be used to tailor the density and mechanical properties of the final porous structures.

CHARACTERIZATION OF HYDROXYAPATITE/TI6AL4V COMPOSITE POWDER UNDER VARIOUS SINTERING TEMPERATURE

2015 ◽  
Vol 75 (7) ◽  
Author(s):  
Amir Arifin ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Junaidi Syarif
Keyword(s):  
Mechanical Properties ◽  
Composite Powder ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Different Temperatures ◽  
Two Phases ◽  
Work Interaction

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature. 

Reinforcing of Porous Hydroxyapatite Ceramics with Hydroxyapatite Fibres for Enhanced Bone Tissue Engineering

2011 ◽  
Vol 10 ◽  
pp. 67-73 ◽  
Author(s):  
Lie Feng Liang ◽  
Xiao Yi Han ◽  
Xiao Cai Yan ◽  
Jie Weng
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Test Machine ◽  
Porous Structures ◽  
X Ray Diffraction ◽  
Porous Hydroxyapatite ◽  
Hydroxyapatite Ceramics ◽  
Ceramic Implants

Porous hydroxyapatite (HA) ceramic implants have attracted attention in bone tissue engineering due to their excellent bioactivity and biocompatibility due to their chemical similarity with the mineral component of natural bone. Unfortunately, HA when is formed into porous structures exhibits very low compression strength. In this study, fabrication of porous HA ceramic scaffolds containing HA fibers is presented. The primary aim of the study is to improve mechanical properties of the scaffold by introducing the fiber with uniform component relative to the scaffold. Scanning electron microscopy was used to observe the surface morphology and pore size of the scaffold. X-ray diffraction (XRD) was used to detect the phase composition and crystallinity of the scaffold. The compressive strength was determined using a universal material test machine. The results and the characterizations demonstrate the addition of HA fiber could enhance the uniformity of mechanical properties among samples and also the strength for a given open porosity.

Development and Evaluation of Mechanical Properties of Al/Ilmenite Nanocomposite

2014 ◽  
Vol 704 ◽  
pp. 32-38
Author(s):  
Lanka Rasidhar ◽  
A. Rama Krishna ◽  
Ch. Srinivasa Rao ◽  
K. Vijaya Lakshmi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Secondary Phase ◽  
Stir Casting ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Scanning Electron

In the present investigation, microstructure and mechanical properties of nanocomposites fabricated via stir casting were evaluated. The composites were based on Al (99.7) reinforced with ilmenite nanoparticles. The characterization of the nanoparticles and nanocomposites was investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) facilities. Microstructure of specimens show that reasonable distribution of FeTiO3 nanoparticles in the matrix, secondary phase FeAl3 observed in the microstructure. Ultimate tensile strength and compression tests were carried out in order to identify the mechanical properties. The hardness of the composites is enhanced with the addition of nanoparticles. The optimum value for ultimate tensile and compression strength are obtained with the addition of 3 % ilmenite nanoparticles. Ductile fracture in tensile fractured samples was observed by fractrography examination.

Production and Mechanical Properties of Commercial Synthetic Hydroxyapatite (CSHA) Composites

2013 ◽  
Vol 587 ◽  
pp. 147-153
Author(s):  
N. Demirkol ◽  
F.N. Oktar ◽  
E.S. Kayali
Keyword(s):  
Mechanical Properties ◽  
Bone Growth ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
Broken Bones ◽  
Metallic Biomaterials ◽  
Different Temperatures ◽  
Density Values ◽  
Synthetic Hydroxyapatite

Hydroxyapatite (HA), one of the calcium phosphate compounds, is the most widely used bioceramic. HA materials have a common usage in bone repairing due to its ability to accelerate the bone growth around the implant. HA is a biocompatible material and used in production of various kinds of prosthesis, repairing the cracked or broken bones and coating of metallic biomaterials. This study covers production and characterization of composite materials made of commercial synthetic hydroxyapatite (CSHA) with commercial inert glass, magnesium oxide and niobium (V) oxide additions (5 and 10 wt%), seperately. These additives used as reinforcement materials to improve the mechanical properties of CSHA based composites. The composites were subjected to sintering at different temperatures between 1000oC and 1300oC, then microstructures and mechanical properties of CSHA composites were investigated. The physical and mechanical properties were determined by measuring density, compression strength and Vickers microhardness (HV). Structural characterization was carried out with X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies. In all composites, density values and mechanical properties increased with increasing sintering temperature. CSHA composite with 5 wt% CIG addition showed highest physical and mechanical properties among all CSHA composites produced in this study.

Comparison of Mechanical Properties of Sheep Hydroxyapatite (SHA) and Commercial Synthetic Hydroxyapatite (CSHA)-MgO Composites

2011 ◽  
Vol 493-494 ◽  
pp. 588-593 ◽  
Author(s):  
N. Demirkol ◽  
Onur Meydanoglu ◽  
Hasan Gökçe ◽  
F.N. Oktar ◽  
E.S. Kayali
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Vickers Microhardness ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
X Ray Diffraction ◽  
Time Saving ◽  
X Ray ◽  
Density Values ◽  
Synthetic Hydroxyapatite

In this study, microstructures and mechanical properties of sheep hydroxyapatite (SHA) and commercial synthetic hydroxyapatite (CSHA)-MgO composites were investigated. The production of hydroxyapatite (HA) from natural sources is preferred due to economical and time saving reasons. The goal of development of SHA and CSHA based MgO composites is to improve mechanical properties of HA. SHA and CSHA composites were prepared with the addition of different amounts of MgO and sintered at the temperature range of 1000-1300 °C. The physical and mechanical properties were determined by measuring density, compression strength and Vickers microhardness (HV). Structural characterization was carried out with X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies. In all composites, mean density values and mechanical properties increased with increasing sintering temperature. The increase of MgO content in SHA-MgO composites showed better mechanical properties in contrast to CSHA-MgO composites. Although the highest hardness and compression strength values were obtained at the SHA-10wt% MgO composite sintered at 1300°C, higher hardness and compression strength values were achieved with 5 wt% MgO addition at the CSHA-MgO composites when compared to SHA-MgO composites sintered between 1000-1200°C.

scholarly journals Effects of Sintering Temperature on Densification, Microstructure and Mechanical Properties of Al-Based Alloy by High-Velocity Compaction

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Velocity ◽  
Sintered Density ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
High Velocity Compaction ◽  
Sintered Temperature

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of Al2O3-TiC-ZrO2 Ceramic Composites

2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Relative Density ◽  
Sintering Temperature ◽  
Ceramic Composites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.

scholarly journals Fabrication and Characterization of Electrospun Polycaprolactone Blended with Chitosan-Gelatin Complex Nanofibrous Mats

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongfang Qian ◽  
Zhen Zhang ◽  
Laijiu Zheng ◽  
Ruoyuan Song ◽  
Yuping Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Weight Ratio ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Tissue Engineering Scaffolds ◽  
Elongation At Break ◽  
Nanofibrous Scaffolds ◽  
Two Peaks

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.

Magnetodielectric Ni ferrite ceramics with Bi2O3 additive for potential antenna miniaturizations

2009 ◽  
Vol 24 (2) ◽  
pp. 324-332 ◽  
Author(s):  
X.T. Liew ◽  
K.C. Chan ◽  
L.B. Kong
Keyword(s):  
Magnetic Properties ◽  
Dielectric Loss ◽  
Grain Growth ◽  
Sintering Temperature ◽  
Magnetic Loss ◽  
Liquid Phase Sintering ◽  
X Ray Diffraction ◽  
Low Dielectric ◽  
High Concentrations

This paper reports on the preparation and characterization of nickel ferrite (NiFe1.98O4) ceramics doped with Bi2O3 as sintering aid. Focus has been on the effects of concentration of Bi2O3 and sintering temperature on the densification, grain growth, dielectric, and magnetic properties of the NiFe1.98O4 ceramics, with an aim at developing magnetodielectric properties, with almost equal real permeability and permittivity, as well as sufficiently low magnetic and dielectric loss tangents, over 3 to 30 MHz (high frequency or HF band). X-ray diffraction results indicated that there is no obvious reaction between NiFe1.98O4 and Bi2O3, at Bi2O3 levels of up to 7 wt% and temperatures up to 1150 °C. The addition of Bi2O3 facilitated a liquid phase sintering mechanism for the densification of NiFe1.98O4 ceramics. The addition of Bi2O3 not only improved the densification but also promoted the grain growth of NiFe1.98O4 ceramics. To achieve sufficiently low dielectric loss tangent, the concentration of Bi2O3 should not be less than 5 wt%. The low dielectric loss tangents of the samples doped with high concentrations of Bi2O3 can be attributed to the full densification of the ceramics. Magnetic properties of the NiFe1.98O4 ceramics, as a function of sintering temperature and Bi2O3 concentration, can be qualitatively explained by the Globus model. Promising magnetodielectric properties have been obtained in the sample doped with 5% Bi2O3 and sintered at 1050 °C for 2 h. The sample has almost equal values of permeability and permittivity of ∼12, together with low dielectric and magnetic loss tangents, over 3 to 30 MHz. This material might be useful for the miniaturization of HF (3 to 30 MHz) antennas.

scholarly journals Copper Containing Glass-Based Bone Adhesives for Orthopaedic Applications: Glass Characterization and Advanced Mechanical Evaluation

2020 ◽  
Author(s):  
Sahar. Mokhtari ◽  
Anthony.W. Wren
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Viscoelastic Behavior ◽  
Polymer Chains ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compression Data

AbstractThis study addresses issues with currently used bone adhesives, by producing novel glass based skeletal adhesives through modification of the base glass composition to include copper (Cu) and by characterizing each glass with respect to structural changes. Bioactive glasses have found applications in fields such as orthopedics and dentistry, where they have been utilized for the restoration of bone and teeth. The present work outlines the formation of flexible organic-inorganic polyacrylic acid (PAA) – glass hybrids, commercial forms are known as glass ionomer cements (GICs). Initial stages of this research will involve characterization of the Cu-glasses, significant to evaluate the properties of the resulting adhesives. Scanning electron microscopy (SEM) of annealed Cu glasses indicates the presence of partial crystallization in the glass. The structural analysis of the glass using Raman suggests the formation of CuO nanocrystals on the surface. X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy (XPS) further confirmed the formation of crystalline CuO phases on the surface of the annealed Cu-glass. The setting reaction was studied using Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the Cu containing adhesives exhibited gel viscoelastic behavior and enhanced mechanical properties when compared to the control composition. Compression data indicated the Cu glass adhesives were efficient at energy dissipation due to the reversible interactions between CuO nano particles and PAA polymer chains.

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