The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Bai Yang Lou - One of the best experts on this subject based on the ideXlab platform.
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improving tribological and corrosion resistance of ti6al4v alloy by hybrid microarc oxidation Enameling treatments
Rare Metals, 2018Co-Authors: Jie Jin, Bai Yang LouAbstract:A promising duplex coating was prepared by microarc oxidation (MAO) and Enameling processes onto polished Ti6Al4V alloy. The TiO2 ceramic coating deposited by MAO was characterized and then combined with an Enameling treatment in order to improve the tribological and corrosion resistance of Ti6Al4V alloy. The morphology, phase composition, and hardness of MAO and MAO/Enameling-coated Ti6Al4V alloy were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Vickers microhardness tester, respectively. The tribological performance was investigated using a ball-on-disk tribometer. The corrosion resistance was studied using immersion tests and potentiodynamic polarization. Wear tests show that the enamel coating on the MAO-coated surface causes a reduction in the friction coefficient. Immersion tests demonstrate that the duplex coating is more effective in improving the corrosion resistance of Ti6Al4V than the MAO coating especially at high temperature (80 °C). Potentiodynamic polarization curves reveal that the corrosion potential of the duplex coating increases by about 250 mV and the corrosion current density is slightly lower than that of the MAO coating. The duplex coating is superior to the stand-alone MAO coating in improving the tribological and corrosion behavior of Ti6Al4V.
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Improving tribological and corrosion resistance of Ti6Al4V alloy by hybrid microarc oxidation/Enameling treatments
Rare Metals, 2015Co-Authors: Jie Jin, Xiao-han Li, Ji-wen Wu, Jian Jun Wu, Xu Li, Bai Yang LouAbstract:A promising duplex coating was prepared by microarc oxidation (MAO) and Enameling processes onto polished Ti6Al4V alloy. The TiO2 ceramic coating deposited by MAO was characterized and then combined with an Enameling treatment in order to improve the tribological and corrosion resistance of Ti6Al4V alloy. The morphology, phase composition, and hardness of MAO and MAO/Enameling-coated Ti6Al4V alloy were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Vickers microhardness tester, respectively. The tribological performance was investigated using a ball-on-disk tribometer. The corrosion resistance was studied using immersion tests and potentiodynamic polarization. Wear tests show that the enamel coating on the MAO-coated surface causes a reduction in the friction coefficient. Immersion tests demonstrate that the duplex coating is more effective in improving the corrosion resistance of Ti6Al4V than the MAO coating especially at high temperature (80 °C). Potentiodynamic polarization curves reveal that the corrosion potential of the duplex coating increases by about 250 mV and the corrosion current density is slightly lower than that of the MAO coating. The duplex coating is superior to the stand-alone MAO coating in improving the tribological and corrosion behavior of Ti6Al4V.
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Improving tribological and corrosion resistance of Ti6Al4V alloy by hybrid microarc oxidation/Enameling treatments
Rare Metals, 2015Co-Authors: Jie Jin, Xiao-han Li, Ji-wen Wu, Jian Jun Wu, Xu Li, Bai Yang LouAbstract:A promising duplex coating was prepared by microarc oxidation (MAO) and Enameling processes onto polished Ti6Al4V alloy. The TiO2 ceramic coating deposited by MAO was characterized and then combined with an Enameling treatment in order to improve the tribological and corrosion resistance of Ti6Al4V alloy. The morphology, phase composition, and hardness of MAO and MAO/Enameling-coated Ti6Al4V alloy were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Vickers microhardness tester, respectively. The tribological performance was investigated using a ball-on-disk tribometer. The corrosion resistance was studied using immersion tests and potentiodynamic polarization. Wear tests show that the enamel coating on the MAO-coated surface causes a reduction in the friction coefficient. Immersion tests demonstrate that the duplex coating is more effective in improving the corrosion resistance of Ti6Al4V than the MAO coating especially at high temperature (80 °C). Potentiodynamic polarization curves reveal that the corrosion potential of the duplex coating increases by about 250 mV and the corrosion current density is slightly lower than that of the MAO coating. The duplex coating is superior to the stand-alone MAO coating in improving the tribological and corrosion behavior of Ti6Al4V.
Niklaus P. Lang - One of the best experts on this subject based on the ideXlab platform.
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Expression of phosphoproteins and amelotin in teeth.
International journal of molecular medicine, 2007Co-Authors: Beat Trueb, Sara Taeschler, Christof Schild, Niklaus P. LangAbstract:The organic material of our teeth consists of collagens and a number of calcium-binding phosphoproteins. Six of these phosphoproteins have recently been grouped in the family of the SIBLINGs (small integrin-binding ligand, N-linked glycoproteins), namely osteopontin, bone sialoprotein, dentin matrix protein (DMP1), dentin sialophosphoprotein (DSPP), matrix extracellular phosphoglycoprotein (MEPE) and enamelin. We prepared a cDNA library from rat incisors in order to identify the genes involved in tooth formation. The library was screened by subtractive hybridization with two probes; one specific for teeth, the other for bone. We found that the vast majority of the clones from our library were expressed at similar levels in bone and teeth, demonstrating the close relationship of the two tissues. Only 7% of all the clones were expressed in a tooth-specific fashion. These included clones for the enamel proteins; amelotin, amelogenin, ameloblastin and enamelin; for the dentin proteins DSPP and DMP1; and for the intermediate filament protein cytokeratin 13. Several typical bone proteins, including collagen I, osteocalcin, alkaline phosphatase and FATSO, were also expressed at significantly higher levels in teeth than in bone, probably due to the extreme growth rate of rat incisors. The amino acid sequence of rat amelotin showed 62% identity with the sequence from humans. It was expressed considerably later than the other enamel proteins, suggesting that amelotin may serve a function different from those of amelogenin, ameloblastin and enamelin.
Hayato Ohshima - One of the best experts on this subject based on the ideXlab platform.
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Rat wct mutation prevents differentiation of maturation-stage ameloblasts resulting in hypo-mineralization in incisor teeth
Histochemistry and Cell Biology, 2007Co-Authors: Masaru Osawa, Shin Kenmotsu, Taku Masuyama, Kazuyuki Taniguchi, Takashi Uchida, Chikara Saito, Hayato OhshimaAbstract:A recent study provided genetic and morphological evidence that rat autosomal-recessive mutation, whitish chalk-like teeth ( wct ), induced tooth enamel defects resembling those of human amelogenesis imperfecta (AI). The wct locus maps to a specific interval of rat chromosome 14 corresponding to human chromosome 4q21 where the ameloblastin and enamelin genes exist, although these genes are not included in the wct locus. The effect of the wct gene mutation on the enamel matrix synthesis and calcification remains to be elucidated. This study clarifies how the wct gene mutation influences the synthesis of enamel matrix and its calcification by immunocytochemistry for amelogenin, ameloblastin and enamelin, and by electron probe micro-analysis (EPMA). The immunoreactivity for enamel proteins such as amelogenin, ameloblastin, and enamelin in the ameloblasts in the homozygous teeth was the same as that in the heterozygous teeth from secretory to transitional stages, although the homozygous ameloblasts became detached from the enamel matrix in the transitional stage. The flattened ameloblasts in the maturation stage of the homozygous samples contained enamel proteins in their cytoplasm. Thus, the wct mutation was found to prevent the morphological transition of ameloblasts from secretory to maturation stages without disturbing the synthesis of enamel matrix proteins, resulting in the hypo-mineralization of incisor enamel and cyst formation between the enamel organ and matrix. This mutation also prevents the transfer of iron into the enamel.
Jie Jin - One of the best experts on this subject based on the ideXlab platform.
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improving tribological and corrosion resistance of ti6al4v alloy by hybrid microarc oxidation Enameling treatments
Rare Metals, 2018Co-Authors: Jie Jin, Bai Yang LouAbstract:A promising duplex coating was prepared by microarc oxidation (MAO) and Enameling processes onto polished Ti6Al4V alloy. The TiO2 ceramic coating deposited by MAO was characterized and then combined with an Enameling treatment in order to improve the tribological and corrosion resistance of Ti6Al4V alloy. The morphology, phase composition, and hardness of MAO and MAO/Enameling-coated Ti6Al4V alloy were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Vickers microhardness tester, respectively. The tribological performance was investigated using a ball-on-disk tribometer. The corrosion resistance was studied using immersion tests and potentiodynamic polarization. Wear tests show that the enamel coating on the MAO-coated surface causes a reduction in the friction coefficient. Immersion tests demonstrate that the duplex coating is more effective in improving the corrosion resistance of Ti6Al4V than the MAO coating especially at high temperature (80 °C). Potentiodynamic polarization curves reveal that the corrosion potential of the duplex coating increases by about 250 mV and the corrosion current density is slightly lower than that of the MAO coating. The duplex coating is superior to the stand-alone MAO coating in improving the tribological and corrosion behavior of Ti6Al4V.
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Improving tribological and corrosion resistance of Ti6Al4V alloy by hybrid microarc oxidation/Enameling treatments
Rare Metals, 2015Co-Authors: Jie Jin, Xiao-han Li, Ji-wen Wu, Jian Jun Wu, Xu Li, Bai Yang LouAbstract:A promising duplex coating was prepared by microarc oxidation (MAO) and Enameling processes onto polished Ti6Al4V alloy. The TiO2 ceramic coating deposited by MAO was characterized and then combined with an Enameling treatment in order to improve the tribological and corrosion resistance of Ti6Al4V alloy. The morphology, phase composition, and hardness of MAO and MAO/Enameling-coated Ti6Al4V alloy were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Vickers microhardness tester, respectively. The tribological performance was investigated using a ball-on-disk tribometer. The corrosion resistance was studied using immersion tests and potentiodynamic polarization. Wear tests show that the enamel coating on the MAO-coated surface causes a reduction in the friction coefficient. Immersion tests demonstrate that the duplex coating is more effective in improving the corrosion resistance of Ti6Al4V than the MAO coating especially at high temperature (80 °C). Potentiodynamic polarization curves reveal that the corrosion potential of the duplex coating increases by about 250 mV and the corrosion current density is slightly lower than that of the MAO coating. The duplex coating is superior to the stand-alone MAO coating in improving the tribological and corrosion behavior of Ti6Al4V.
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Improving tribological and corrosion resistance of Ti6Al4V alloy by hybrid microarc oxidation/Enameling treatments
Rare Metals, 2015Co-Authors: Jie Jin, Xiao-han Li, Ji-wen Wu, Jian Jun Wu, Xu Li, Bai Yang LouAbstract:A promising duplex coating was prepared by microarc oxidation (MAO) and Enameling processes onto polished Ti6Al4V alloy. The TiO2 ceramic coating deposited by MAO was characterized and then combined with an Enameling treatment in order to improve the tribological and corrosion resistance of Ti6Al4V alloy. The morphology, phase composition, and hardness of MAO and MAO/Enameling-coated Ti6Al4V alloy were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Vickers microhardness tester, respectively. The tribological performance was investigated using a ball-on-disk tribometer. The corrosion resistance was studied using immersion tests and potentiodynamic polarization. Wear tests show that the enamel coating on the MAO-coated surface causes a reduction in the friction coefficient. Immersion tests demonstrate that the duplex coating is more effective in improving the corrosion resistance of Ti6Al4V than the MAO coating especially at high temperature (80 °C). Potentiodynamic polarization curves reveal that the corrosion potential of the duplex coating increases by about 250 mV and the corrosion current density is slightly lower than that of the MAO coating. The duplex coating is superior to the stand-alone MAO coating in improving the tribological and corrosion behavior of Ti6Al4V.
Sally J. Marshall - One of the best experts on this subject based on the ideXlab platform.
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bioactive glass coatings with hydroxyapatite and bioglass particles on ti based implants 1 processing
Biomaterials, 2000Co-Authors: J M Gomezvega, Eduardo Saiz, Antoni P Tomsia, Grayson W. Marshall, Sally J. MarshallAbstract:Silicate-based glasses with thermal expansion coe$cients that match those of Ti6Al4V were prepared and used to coat Ti6Al4V by a simple Enameling technique. Bioglasst (BG) or hydroxyapatite (HA) particles were embedded on the coatings in order to enhance their bioactivity. HA particles were immersed partially during heating and remained "rmly embedded on the coating after cooling. There was no apparent reaction at the glass/HA interface at the temperatures used in this work (800}8403C). In contrast, BG particles softened and some in"ltration into the glass coating took place during heat treatment. In this case, particles with sizes over 45 lm were required, otherwise the particles became hollow due to the in"ltration and crystallization of the glass surface. The concentration of the particles on the coating was limited to 20% of surface coverage. Concentrations above this value resulted in cracked coatings due to excessive induced stress. Cracks did not propagate along the interfaces when coatings were subjected to Vickers indentation tests, indicating that the particle/glass and glass/metal interfaces exhibited strong bonds. Enameling, producing excellent glass/metal adhesion with well-attached bioactive particles on the surface, is a promising method of forming reliable and lasting implants which can endure substantial chemical and mechanical stresses. ( 1999 Elsevier Science Ltd. All rights reserved.
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A multilayer approach to fabricate bioactive glass coatings on Ti alloys
MRS Proceedings, 1998Co-Authors: J. M. Gomez-vega, Eduardo Saiz, Antoni P Tomsia, Grayson W. Marshall, Sally J. MarshallAbstract:Glasses in the system Si-Ca-Na-Mg-P-K-O with thermal expansion coefficients close to that of Ti6Al4V were used to coat the titanium alloy by a simple Enameling technique. Firings were done in air at temperatures between 800 and 840 C and times up to 1 minute. Graded compositions were obtained by firing multilayered glass coatings. Hydroxyapatite (HA) particles were mixed with the glass powder and the mixture was placed on the outer surface of the coatings to render them more bioactive. Coatings with excellent adhesion to the substrate and able to form apatite when immersed in a simulated body fluid (SBF) can be fabricated by this methodology.