共查询到6条相似文献,搜索用时 0 毫秒
1.
Hidetoshi Miyazaki Isao Ushiroda Daisuke Itomura Tsunehisa Hirashita Nobuyasu Adachi Toshitaka Ota 《Materials science & engineering. C, Materials for biological applications》2009,29(4):1463-1466
Hydroxy apatite (HAp) ceramic was synthesized using traditional sintering. Dilatometric and lattice thermal expansion properties of a HAp ceramic were evaluated at temperatures of ? 100–50 °C. In that temperature range, the dilatometric thermal expansion coefficient and the lattice thermal expansion coefficient of the HAp ceramic were, respectively, 10.6 × 10? 6/°C and 9.9 × 10? 6/°C. Furthermore, thermal expansion properties of a human tooth were measured. The thermal expansion coefficient of the horizontal direction perpendicular to the growing direction of a tooth was 15.5 × 10? 6/°C; that of the vertical direction along with the direction of tooth growth was 18.9 × 10? 6/°C at the temperature range described above. 相似文献
2.
Neslihan Temizel Giray Girisken A. Cuneyt Tas 《Materials science & engineering. C, Materials for biological applications》2011,31(5):1136-1143
This study investigated the hydrothermal transformation of brushite (dicalcium phosphate dihydrate, DCPD, CaHPO4·2H2O) into octacalcium phosphate (OCP, Ca8(HPO4)2(PO4)4·5H2O) in seven different newly developed biomineralization media, all inspired from the commercial DMEM solutions, over the temperature range of 36.5 °C to 90 °C with aging times varying between 1 h and 6 days. DCPD powders used in this study were synthesized in our laboratory by using a wet-chemical technique. DCPD was found to transform into OCP in the Ca2+, Mg2+, Na+, K+, HCO3?, Cl? and H2PO4? containing aqueous biomineralization media in less than 72 h at 36.5 °C, without stirring. The same medium was able to convert DCPD into OCP in about 2 h at 75–80 °C, again without a need for stirring. Samples were characterized by using powder X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). 相似文献
3.
Journal of Materials Science - Organic and inorganic acid catalysts enable control over the sol–gel synthesis of crystalline TiO2 nanoparticles. While the mechanism of organic acids (e.g.,... 相似文献
4.
Ni3Al matrix self-lubricating composites (NMSC) containing varied amounts of WS2, Ag and hBN (WAh) with weight ratio of 1:1:1 were fabricated by in situ technique using spark plasma sintering. The friction and wear properties of NMSC against the commercial Si3N4 ceramic ball at the load of 10 N and sliding speed of 0.234 m/s for 80 min from room temperature to 800 °C were investigated. The results showed that the tribological properties of NMSC strongly depended on the addition content of WAh. Moreover, NMSC with 15 wt.% WAh and 5 wt.% TiC exhibited the relatively lower friction coefficients and the less wear rates from RT to 800 °C. The excellent tribological behavior of NMSC with 15 wt.% WAh and 5 wt.% TiC was attributed to the synergetic action of composite lubricants of WAh and reinforced phase of TiC. 相似文献
5.
Dry sliding tribological behaviors of TiAl matrix self-lubricating composites (TMSC) containing varying amounts of Ag, Ti3SiC2 and BaF2/CaF2 eutectic (BaF2–38 wt.%CaF2) (ATBC) with weight ratio of 1:1:1 against Si3N4 from room temperature (RT) to 600 °C at the condition of 10 N–0.234 m/s were experimentally studied. The results implied that the ATBC could improve friction-reducing and anti-wear ability of TMSC over an extreme range of operating temperatures, which was attributed to the synergetic effect of Ag, Ti3SiC2 and BaF2/CaF2 lubricants. In addition, TMSC containing 9 wt.% ATBC exhibited the best tribological properties over the wide temperature range from RT to 600 °C. 相似文献
6.
The metal stoichiometry ranges of the Ln2 − x
Mn
x
O3 ± δ (Ln = Y, Ho, Er) manganites have been determined using X-ray diffraction analysis of ceramic samples prepared by reacting
oxide mixtures in air at temperatures from 900 to 1400°C. The results are represented as partial phase diagrams of the Ln-Mn-O
systems in air. Comparison of the phase diagrams demonstrates that the phase boundaries of the manganites are determined not
only by the effective cation radius of the rare-earth metal. The solubilities of the binary oxides Y2O3, Ho2O3, and Mn3O4 in yttrium and holmium manganites increase with temperature, with significant quantitative distinctions. The Er2O3 and Mn3O4 solubilities in erbium manganite remain unchanged over the entire temperature range studied. The LnMn2O5 solubility in LnMnO3 ± δ is an intricate function of temperature. We analyze the possible causes of the Ln2O3, Mn3O4, and LnMn2O5 solubility in the LnMnO3 ± δ (Ln = Y, Ho, Er) manganites. 相似文献