Authors: Ik Hyun Oh, Hyeon Taek Son, Chang Seog Kang, Jae Seol Lee, Jae Ik Cho, Jung Chan Bae, Byong Taek Lee, Ho Yeon Song
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Authors: Pongporn Moonchaleanporn, Nuchthana Poolthong, Ruangdaj Tongsri
Abstract: The design of engineered bone substitutes takes biocompatibility and mechanical compatibility into account as prerequisite requirements. Titanium (Ti) and hydroxyapatite (HA) with chemical formula of Ca10(PO4)6(OH)2, show good biocompatibility and are known as biomaterials. To combine metal powder (Ti) and ceramic powder (HA) as a composite material with mechanical properties comparable to those of natural bones needs strategy. In this work, powder metallurgy process was employed to produce Ti-HA composites, with nominal HA powder contents in the range of 0-100 vol.%. Mixtures of Ti and HA powders were pressed in a rigid die. Sintering was performed in vacuum atmosphere. The as-sintered specimens were tested on biocompatibility in a human-osteoblast cells. It was found that processing and materials parameters, including compaction pressure, control the composite microstructures and mechanical properties. Laboratory bone tissue culturing showed that a bone tissue could grow on the artificial bones (sintered Ti-HA composites).
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Authors: Hasmaliza Mohamad, Yu Min Lim
Abstract: Porous cordierite is an advanced ceramic which is popular for its interesting properties such as excellent thermal stability, high refractoriness and low dielectric constant. In this study, samples have been prepared by the mixture of aluminium nitrate nonahydrate, magnesium nitrate hexahydrate, tetraethylorthosilicate (TEOS), ethanol and nitric acid through sol-gel route. Corn and potato starch were used as pore forming agent. The amount of pore forming agent added was varied according to their weight percent (5wt%, 10wt%, 15wt% and 20wt%). The solution was then dried in oven at 90°C before sintered at 1350°C. Particle size analyzer was used to characterize the properties of pore forming agents. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were done on the produced samples. XRD results proved that all the samples produced were pure α-cordierite without the presence of other impurity or pore forming agent. From SEM results, samples using potato starch as the pore forming agent have pore size larger than corn starch due to the larger particle size of potato starch. Majority of the samples show interconnectivity among pores. The pore shape produced by potato starch is in prolate shape whereas for corn starch is in polyhedral shape.
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