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Rafieerad A.R.,University of MalayaKuala Lumpur | Ashra M.R.,University of MalayaKuala Lumpur | Mahmoodian R.,University of MalayaKuala Lumpur | Mahmoodian R.,Azarin Kar Ind. Co. | Bushroa A.R.,University of MalayaKuala Lumpur
Materials Science and Engineering C | Year: 2015

In recent years, calcium phosphate-base composites, such as hydroxyapatite (HA) and carbonate apatite (CA) have been considered desirable and biocompatible coating layers in clinical and biomedical applications such as implants because of the high resistance of the composites. This review focuses on the effects of voltage, time and electrolytes on a calcium phosphate-base composite layer in case of pure titanium and other biomedical grade titanium alloys via the plasma electrolytic oxidation (PEO) method. Remarkably, these parameters changed the structure, morphology, pH, thickness and crystallinity of the obtained coating for various engineering and biomedical applications. Hence, the structured layer caused improvement of the biocompatibility, corrosion resistance and assignment of extra benefits for Osseo integration. The fabricated layer with a thickness range of 10 to 20 μm was evaluated for physical, chemical, mechanical and tribological characteristics via XRD, FESEM, EDS, EIS and corrosion analysis respectively, to determine the effects of the applied parameters and various electrolytes on morphology and phase transition. Moreover, it was observed that during PEO, the concentration of calcium, phosphor and titanium shifts upward, which leads to an enhanced bioactivity by altering the thickness. The results confirm that the crystallinity, thickness and contents of composite layer can be changed by applying thermal treatments. The corrosion behavior was investigated via the potentiodynamic polarization test in a body-simulated environment. Here, the optimum corrosion resistance was obtained for the coating process condition at 500 V for 15 min in Ringer solution. This review has been summarized, aiming at the further development of PEO by producing more adequate titanium-base implants along with desired mechanical and biomedical features. © 2015 Elsevier B.V.

Mahmoodian R.,University of Malaya | Mahmoodian R.,Azarin Kar Ind. Co. | Rahbari R.G.,University of Toronto | Hamdi M.,University of Malaya | Sparham M.,University of Malaya
High Temperature Material Processes | Year: 2012

In order to conduct centrifugal thermite research experiments in the laboratory, a special apparatus is required. A self-propagating high temperature synthesis machine with acceleration up to 350g was fabricated to accomplish experiments in laboratory settings. Then, thermite reaction of Ferro oxide III and Aluminium inside a pipe was performed to produce Alumina ceramic in the innermost layer and Ferro layer. Combustion synthesis is characterized by extreme heating rate, high temperature, and short reaction time. Centrifugal force facilitated the phase separation of multi-component products during the process. Preliminary tests were conducted prior to fabrication to realize reaction conditions. Ceramic-lined composite pipe by less than 100 mm length and 70 mm diameter with micro-hardness of 2365HV was produced. ©2012 by Begell House, Inc.

Mahmoodian R.,University of Malaya | Mahmoodian R.,Azarin Kar Ind. Co. | Hassan M.A.,University of Malaya | Hassan M.A.,Assiut University | Bin Abd Shukor M.H.,University of Malaya
Ceramic Engineering and Science Proceedings | Year: 2016

A fundamental study was conducted to investigate the Ti-C system when it is exposed to a hybrid reaction between thermite and elemental powders of titanium and carbon under centrifugal acceleration. A pellet of Ti+C was fixed in an offset position relative to the surrounding steel tube in the reaction chamber, which was filled with thermite mixture. The aluminothermic mixture was ignited; it generated a massive amount of heat and was able to initiate a secondary reaction. The secondary Ti+C reaction was affected by the high temperature. Several byproducts were formed, including intermetallics. A microstructure and phase analysis of the synthesized product are investigated in this paper, revealing 27% formation of a new product with 796 MPa hardness. The study explains how the Ti+C behaved during a short and sudden heating environment.

Mahmoodian R.,University of Malaya | Mahmoodian R.,Azarin Kar Ind. Co. | Hamdi M.,University of Malaya | Hassan M.A.,University of Malaya | And 2 more authors.
PLoS ONE | Year: 2015

Titanium carbide-graphite (TiC/C) composite was successfully synthesized from Ti and C starting elemental powders using self-propagating high-temperature synthesis technique in an ultra-high plasma inert medium in a single stage. The TiC was exposed to a high-temperature inert medium to allow recrystallization. The product was then characterized using field emission scanning electron microscopy (FESEM) coupled with energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD), Rietveld refinement, nanoindentation, and microhardness to determine the product's properties. The recorded micro-hardness of the product was 3660 HV, which is a 14% enhancement and makes is comparable to TiC materials. © 2015 Mahmoodian et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Mahmoodian R.,University of Malaya | Mahmoodian R.,Azarin Kar Ind. Co. | Hassan M.A.,University of Malaya | Hassan M.A.,Assiut University | And 2 more authors.
Combustion Science and Technology | Year: 2014

The purpose of this article is to synthesize a Ti-C system under a known cooling rate by applying a secondary hybrid system in the form of semi-reacted titanium carbide. The synthesis reaction is performed in a hot, inert, shielded crucible. The portions of reacting and interacting materials are determined using the Rietveld phase quantification method. The product microstructure is studied, and the nanomechanical properties are measured via a nanoindentation technique. The experimental results revealed that the reaction behavior and mechanical properties of Ti+C elemental powder were initiated at a particular temperature level. At 2610°C, the titanium carbide phase formed 14% of the compound composition, with 65 GPa Youngs modulus and 563 MPa hardness. Copyright © 2014 Taylor & Francis Group, LLC.

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