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1

Densification and mechanical behavior of β-tricalcium phosphate bioceramics

Mehdikhani B., Borhani G. H.

International Letters of Chemistry, Physics and Astronomy

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2014

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Vol. 17, iss. 1

37--49

EN

Nano-size β-tricalcium phosphate powders with average grain size of 80 nm were prepared by the wet chemical precipitation method with calcium nitrate and di-ammonium hydrogen phosphate as calcium and phosphorus precursors, respectively. The precipitation process employed was also found to be suitable for the production of sub-micrometre β-TCP powder in situ. The sinterability of the nano-size powders, and the microstructure, mechanical strength of the prepared β-TCP bioceramics were investigated. Bioceramic sample characterization was achieved by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), and density measurements. Powders compacted and sintered at 800, 900, 1000 and 1100 °C showed an increase in relative density from 70 % to 93 %. The results revealed that the maximum hardness of 240 HV was obtained for β-TCP sintered at 1100 °C.

2

Crystallization behavior and microstructure of bio glass-ceramic system

Mehdikhani B., Borhani G. H.

International Letters of Chemistry, Physics and Astronomy

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2013

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Vol. 14

58--68

EN

The effects of Al2O3 on the crystallization behavior of glass compositions in the Na2O-CaO-SiO2 system were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Effect of Al2O3 content on the mechanical, density, phase formation and microstructures of Na2O-CaO–P2O5–Al2O3-SiO2 glass ceramics were studied. Thermal parameters of each glass were studied by DTA. The density of the glass ceramic samples was measured by Archimedes’ method. It was found that the glass–ceramic containing 2.0 molar percent Al2O3 had desirable sintering behavior and reached to an acceptable density. Phase investigation and micro structural study were performed by XRD and SEM, respectively.

3

The effect of compositional changes on the crystallisation behaviour and mechnical properties of Li2O-CaO-SiO2-Al2O3

Mirhadi B., Mehdikhani B.

Advances in Materials Science

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2011

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Vol. 11, nr 4(30)

11-21

EN

The crystallisation characteristics of glasses based on the Li2O–CaO–SiO2-Al2O3(LCSA) system containing TiO2, ZrO2 has been investigated by differential thermal analysis (DTA), X-ray diffraction analysis (XRD), and scanning electron microscopy (SEM). The partial replacement of Li2O, CaO and SiO2 by TiO2, ZrO2 in the studied glass-ceramics led to the development of different crystalline phase assemblages, including lithium calcium silicates, wollastonite, a-eucryptite and a-spodumene using various heat-treatment processes. The rod-like growth morphology was observed by SEM for glass free of TiO2. In this glass, ZrO2 reduced mobility of boundary at sintering temperature, 1000°C and relatively density was 77%. The most sinterability observed in sample containing TiO2 and free of ZrO2 at sintering temperature, 1000°C and relatively density was 84%.