The Experts below are selected from a list of 41499 Experts worldwide ranked by ideXlab platform
Abbas Fahami - One of the best experts on this subject based on the ideXlab platform.
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influence of titania content on mechanosynthesis of chlorapatite titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman NasiritabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite Nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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synthesis and characterization of chlorapatite zno composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiritabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite Nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite Nanopowder. On increasing the zinc oxide content to 10 wt%, composite Nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite Nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite Nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
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Influence of titania content on mechanosynthesis of chlorapatite–titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman Nasiri-tabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite Nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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Synthesis and characterization of chlorapatite–ZnO composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiri-tabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite Nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite Nanopowder. On increasing the zinc oxide content to 10 wt%, composite Nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite Nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite Nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
Bahman Nasiri-tabrizi - One of the best experts on this subject based on the ideXlab platform.
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Influence of titania content on mechanosynthesis of chlorapatite–titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman Nasiri-tabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite Nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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Synthesis and characterization of chlorapatite–ZnO composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiri-tabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite Nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite Nanopowder. On increasing the zinc oxide content to 10 wt%, composite Nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite Nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite Nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
Bahman Nasiritabrizi - One of the best experts on this subject based on the ideXlab platform.
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influence of titania content on mechanosynthesis of chlorapatite titania composite Nanopowders
Ceramics International, 2014Co-Authors: Abbas Fahami, Bahman NasiritabriziAbstract:Abstract The effect of titania content on mechanochemical synthesis of chlorapatite–titania composite Nanopowders was studied for the first time. According to the obtained data, the phase compositions, structural features as well as morphological characteristics of the composites were influenced by the titania content. In the presence of 3–5 wt% titania, milling for 5 h resulted in the formation of chlorapatite–titania composite Nanopowders. The crystallite size of the samples was around 25±1 and 23±1 nm in the presence of 3 and 5 wt% titania, respectively. With increasing the titania content to 7 wt%, no chemical reaction happened during the milling. The composite Nanopowders showed high volume fraction of grain boundaries. Based on the FT-IR results, the products had high chemical purity which is very important in biomedical applications. The TEM images indicated that the composite Nanopowder was composed of spheroidal particles with a mean size of around 35 nm. The proposed synthesis strategy provides a facile pathway to obtain novel chlorapatite-based composite Nanopowders with high purity and optimal properties.
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synthesis and characterization of chlorapatite zno composite Nanopowders
Ceramics International, 2014Co-Authors: Bahman Nasiritabrizi, Abbas FahamiAbstract:Abstract The influence of zinc oxide content on the formation of chlorapatite-based composite Nanopowders in the mechanically alloyed CaO–CaCl 2 –P 2 O 5 –ZnO system was studied. To mechanosynthesize composite Nanopowders, different amounts of hydrothermally synthesized zinc oxide nanoparticles (0–10 wt%) were mixed with ingredients and then were mechanically activated for 5 h. Results showed that in the absence of zinc oxide, high crystalline chlorapatite Nanopowder was obtained after 5 h of milling. In the presence of 4 and 7 wt% zinc oxide, the main product of milling for 5 h was chlorapatite–zinc oxide composite Nanopowder. On increasing the zinc oxide content to 10 wt%, composite Nanopowder was not formed due to improper stoichiometric ratio of the reactants. The crystallite size, lattice strain, volume fraction of grain boundary, and crystallinity degree of the samples fluctuated significantly during the milling process. In the presence of 7 wt% zinc oxide, the crystallite size and crystallinity degree reached 51±2 nm and 79±2%, respectively. During annealing at 900 °C for 1 h, the crystallization of composite Nanopowder occurred and as a result the crystallinity degree rose sharply to 96±3%. In addition, the crystallite size increased to 77±2 nm after annealing at 900 °C. According to SEM and TEM images, the composite Nanopowder was composed of both ellipse-like and polygonal particles with a mean size of about 98 nm.
Joonphil Choi - One of the best experts on this subject based on the ideXlab platform.
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Compaction behavior of bimodal iron Nanopowder agglomerate
Powder Technology, 2018Co-Authors: Jun-ll Song, Joonphil Choi, Geon-yong Lee, Jai-sung LeeAbstract:Abstract The compaction behavior of structure-modified Fe Nanopowders having agglomerates of spherical shape and a bimodal particle size distribution was investigated in terms of the particle packing and microstructure during compaction process. To fabricate the structure-modified Fe Nanopowders, the spray-dried Fe2O3 Nanopowder was hydrogen reduced at 400, 450 and 550 °C to control the degree of particle growth in agglomerates. The compaction behavior of fabricated Fe Nanopowders was investigated by two different ways. In die compaction experiments, it was found that the bimodal Nanopowder reduced at 550 °C showed higher green density compared to Nanopowders reduced at 400 and 450 °C over the entire range of compacting pressure. Furthermore, the compact of the bimodal Nanopowder achieved a remarkable green density over 80% of theoretical density (TD) at 1000 MPa pressure without any defects due to the effective packing by filling the interstices between the large nanoparticles with small nanoparticles. The obtained density-pressure data was fitted by the Panelli and Ambrozio Filho equation to compare the densification capacity between the fabricated Fe Nanopowders. To investigate the agglomerate deformation occurrence at the low pressure range, a continuous compaction experiment was conducted; the observations were explained in terms of microstructural development on the basis of the apparent yield pressure obtained from continuous densification curves.
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sintering behavior of 316l stainless steel micro Nanopowder compact fabricated by powder injection molding
Powder Technology, 2015Co-Authors: Joonphil Choi, Geon-yong Lee, Junil Song, Wonsik Lee, Jai-sung LeeAbstract:Abstract The densification and grain growth behavior of powder injection molded 316L stainless steel micro–Nanopowder were investigated in terms of microstructural development. The sintered density of the micro–Nanopowder sample increased remarkably in the temperature range of 1000 to 1100 °C due to the sintering effect of Nanopowders which increased the number of grain boundaries acting as high material transport path. A near full density of 98% TD was obtained after sintering at 1100 °C for 5 h with the average grain size less than 10 μm, indicating that there was no drastic grain growth. The presence of Nanopowders in micro–Nanopowder played decisive role in the entire sintering process by enhancing densification but suppressing grain growth. These effects open up the possibility of using micro–Nanopowder feedstock to control the sintering behavior of powder injection molding products with full density and fine microstructure.
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densification and microstructural development during sintering of powder injection molded fe micro Nanopowder
Powder Technology, 2014Co-Authors: Joonphil ChoiAbstract:Abstract The sintering behavior of the powder injection molded Fe micro–Nanopowder fabricated under low temperature and low pressure conditions of 70 °C and 4 MPa was investigated in terms of the microstructural development. It was found that the sintered density of the micro–Nanopowder was remarkably increased in the temperature range of 800 to 900 °C by the Nanopowder effect due to the enhancement of the material transport by grain boundary diffusion. The micrograins in the micro–Nanopowder almost maintained their initial grain size until the sintered density reached 90% of the theoretical density (TD), even showing no drastic grain growth under the condition of full density of 97% TD after sintering at 1250 °C for 3 h. This means that the presence of the Nanopowders not only increases material transport paths for rapid densification but also suppresses the grain growth. The experimental findings in this study provide the potential application of micro–Nanopowders for processing the PIM products with full density and fine microstructure.
A H Naqvi - One of the best experts on this subject based on the ideXlab platform.
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formation and characterization of zno Nanopowder synthesized by sol gel method
Journal of Alloys and Compounds, 2010Co-Authors: Ameer Azam, Faheem Ahmed, Nishat Arshi, M Chaman, A H NaqviAbstract:Abstract ZnO Nanopowder formation through sol–gel route is reported here. Sol was prepared from zinc acetate dihydrate precursor and ethylene glycol as solvent. The resulting solution was highly water sensitive and converted to gel on addition of a few drops of water, final heating in two steps gave ZnO Nanopowder. The properties of the synthesized Nanopowder were studied using AFM, SEM, TEM, XRD, UV–VIS spectrophotometer, FT-IR, and TGA/DTA. The average size of the nanoparticles was determined by TEM as well as XRD data and found to be ∼19 nm. The UV–VIS spectrum of the synthesized Nanopowders indicates a band gap of about 3.44 eV showing a weak blue shift compared to 3.37 eV for the bulk ZnO. Due to their good optical and electrical properties, nanophase ZnO is promising candidate for use as transparent electrodes in solar cells.
