Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Preparation of Titanium Phosphates with Sodium Triphosphate in Hydrothermal Process and Their Powder Properties for Cosmetics  [PDF]
Hiroaki Onoda, Taisuke Yamaguchi
Advances in Materials Physics and Chemistry (AMPC) , 2013, DOI: 10.4236/ampc.2013.31001

As a white pigment, titanium oxide is used for cosmetic application. This oxide is well known to have the photo catalytic activity. Therefore, a certain degree of sebum on the skin is decomposed by the ultraviolet radiation in sunlight. In this work, titanium phosphates were prepared with titanium chloride and sodium triphosphate in hydrothermal process as a novel white pigment. Their chemical composition, powder properties, photo catalytic activity, color phase, and smoothness were studied. The obtained phosphates had little photo catalytic activity. The particle size of phosphate pigments consisted a normal distribution at 2 μm by the hydrothermal treatment for 4 and 8 hours. The slipping resistance of samples became small by the hydrothermal treatment.

Influence of pH and Ultrasonic Treatment on Preparation of Titanium Phosphates and Their Powder Properties  [PDF]
Hiroaki Onoda, Syohei Fujikado
Journal of Materials Science and Chemical Engineering (MSCE) , 2014, DOI: 10.4236/msce.2014.25005

Titanium oxide that has the photocatalytic activity is used as the white pigment for cosmetics. A certain degree of sebum on the skin is decomposed by the ultraviolet radiation in sunlight. In this work, as a novel white pigment, titanium phosphates were prepared from titanium sulfate and phosphoric acid at pH 5, 7, and 9, with/without ultrasonic treatment for cosmetics. Their chemical composition, powder properties, photocatalytic activity, color phase, moisture retention, and smoothness were studied. These titanium phosphates had less photocatalytic activity to protect the sebum on the skin. Sample prepared at pH 7 without ultrasonic treatment had higher moisture retention than other samples. All samples obtained in this work had the suitable smoothness for cosmetics.


LIU Jing-shu,LI Qiang,

腐蚀科学与防护技术 , 2006,
Abstract: Recently, polymer coatings with additives of nano-titanium powder have been gradualy used for water injection system, well tubing and oil pipeling for corrosion prevention. Since 2002, Dongxin Oil Production Factor of Shengli Oilfied has used the coatings for well tubing successfully. In the paper, the performance of the applied coatings was reported based on a survey of corrosion protectivenss of the coated tubings.
Preparation of Composite Additives Powder by Coprecipitation Method and Investgation of ZnO Varistor Ceramics  [PDF]
CHEN Pei-Rong, JI You-Zhang, YANG Qing
无机材料学报 , 2012, DOI: 10.3724/sp.j.1077.2012.12105
Abstract: ZnO varistor ceramic was prepared from composite additives powder synthesized by coprecipitation method. The coprecipitate precursor was investigated by thermogravimetric and differential thermal analysis. Phase formation, morphologies, component elements and particle size distribution of the obtained powder were characterized by X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscope and dynamic laser scattering. Electrical properties of the prepared ZnO varistor ceramics were measured, then microstructure features of the ceramics were also observed. The results show that the mixture powder of each additive oxide is obtained by calcination of the precursor at 550 while the composite additives powder with pyrochlore-type composition of (Bi1.14Co0.26Mn0.29)(Sb1.14Cr0.57Ni0.29)O6.25 and average particle size of 0.26μm is achieved at 650 or 1 h. ZnO varistor ceramic prepared from the resulted composite additives powder exhibits a higher breakdown voltage (Eb=330 V/mm), a higher nonlinearity coefficient (α=47) and a lower leakage current (IL=5μA/cm2) than that prepared from conventional mixed oxide powder. The improvement in electrical properties is attributed to the more uniform microstructure.
Progress in Titanium Metal Powder Injection Molding  [PDF]
Randall M. German
Materials , 2013, DOI: 10.3390/ma6083641
Abstract: Metal powder injection molding is a shaping technology that has achieved solid scientific underpinnings. It is from this science base that recent progress has occurred in titanium powder injection molding. Much of the progress awaited development of the required particles with specific characteristics of particle size, particle shape, and purity. The production of titanium components by injection molding is stabilized by a good understanding of how each process variable impacts density and impurity level. As summarized here, recent research has isolated the four critical success factors in titanium metal powder injection molding (Ti-MIM) that must be simultaneously satisfied—density, purity, alloying, and microstructure. The critical role of density and impurities, and the inability to remove impurities with sintering, compels attention to starting Ti-MIM with high quality alloy powders. This article addresses the four critical success factors to rationalize Ti-MIM processing conditions to the requirements for demanding applications in aerospace and medical fields. Based on extensive research, a baseline process is identified and reported here with attention to linking mechanical properties to the four critical success factors.
Porous titanium scaffolds produced by powder metallurgy for biomedical applications
Vasconcellos, Luana Marotta Reis de;Oliveira, Marize Varella de;Gra?a, Mário Lima de Alencastro;Vasconcellos, Luis Gustavo Oliveira de;Carvalho, Yasmin Rodarte;Cairo, Carlos Alberto Alves;
Materials Research , 2008, DOI: 10.1590/S1516-14392008000300008
Abstract: porous titanium scaffolds are promising materials for biomedical applications such as prosthetic anchors, fillers and bone reconstruction. this study evaluated the bone/titanium interface of scaffolds with interconnected pores prepared by powder metallurgy, using scanning electron microscopy (sem) and energy dispersive spectroscopy (eds). porous scaffolds and dense samples were implanted in the tibia of rabbits, which were subsequently killed 1, 4, and 8 weeks after surgery. initial bone neoformation was observed one week after implantation. bone ingrowth in pores and the ca/p ratio at the interface were remarkably enhanced at 4 and 8 weeks. the results showed that the interconnected pores of the titanium scaffolds promoted bone ingrowth, which increased over time. the powder metallurgy technique thus proved effective in producing porous scaffolds and dense titanium for biomedical applications, allowing for adequate control of pore size and porosity and promoting bone ingrowth.
Photocatalytic Activity of Titanium Dioxide Powder Fabricated from an Anodized Titanium Sheet under Ultra-Violet and Visible Light Irradiation  [PDF]
Michio Kaneko, Kiyonori Tokuno, Kazuo Yamagishi, Takao Wada, Tsuyoshi Hasegawa
Journal of Surface Engineered Materials and Advanced Technology (JSEMAT) , 2017, DOI: 10.4236/jsemat.2017.71002
Abstract: A commercially pure titanium sheet with titanium carbide (TiC) precipitated in its surface layer was anodized in NH4NO3 aqueous solution and heat treated in air. The photocatalytic activity of titanium dioxide powder collected from the surface of the anodized titanium sheet was evaluated under ultra-violet and visible light irradiation. It showed relatively high photocatalytic activity in 0.1 mol/l potassium iodide solution, which was almost equal to the activity level of TiO2 powder (P-25) manufactured by Degussa Corporation. The better photocatalytic activity under ultra-violet irradiation is considered to be related to the formation of anatase type titanium dioxide. Photocatalytic activity under visible light irradiation was also observed, which was considered to be attributable to impurity doping, (carbon), in the titanium dioxide powder.
Production of a low young modulus titanium alloy by powder metallurgy
Santos, Dalcy Roberto dos;Henriques, Vinicius André Rodrigues;Cairo, Carlos Alberto Alves;Pereira, Marcelo dos Santos;
Materials Research , 2005, DOI: 10.1590/S1516-14392005000400014
Abstract: titanium alloys have several advantages over ferrous and non-ferrous metallic materials, such as high strengthto-weight ratio and excellent corrosion resistance. a blended elemental titanium powder metallurgy process has been developed to offer low cost commercial products. the process employs hydride-dehydride (hdh) powders as raw material. in this work, results of the ti-35nb alloy sintering are presented. this alloy due to its lower modulus of elasticity and high biocompatibility is a promising candidate for aerospace and medical use. samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by isochronal sintering between 900 up to 1600 °c, in vacuum. sintering behavior was studied by means of microscopy and density. sintered samples were characterized for phase composition, microstructure and microhardness by x-ray diffraction, scanning electron microscopy and vickers indentation, respectively. samples sintered at high temperatures display a fine plate-like a structure and intergranular b. a few remaining pores are still found and density above 90% for specimens sintered in temperatures over 1500 °c is reached.
Production of titanium alloys for advanced aerospace systems by powder metallurgy
Henriques, Vinicius André Rodrigues;Campos, Pedro Paulo de;Cairo, Carlos Alberto Alves;Bressiani, José Carlos;
Materials Research , 2005, DOI: 10.1590/S1516-14392005000400015
Abstract: titanium alloys parts are ideally suited for advanced aerospace systems because of their unique combination of high specific strength at both room temperature and moderately elevated temperature, in addition to excellent corrosion resistance. despite these features, use of titanium alloys in engines and airframes is limited by cost. the alloys processing by powder metallurgy eases the obtainment of parts with complex geometry. in this work, results of the ti-6al-4v and ti-13nb-13zr alloys production are presented. samples were produced by mixing of initial metallic powders followed by uniaxial and cold isostatic pressing with subsequent densification by sintering between 900 up to 1500 °c, in vacuum. sintered samples were characterized for phase composition, microstructure and microhardness by x-ray diffraction, scanning electron microscopy and vickers indentation, respectively. it was shown that the samples were sintered to high densities and presented homogeneous microstructure from the elements dissolution with low interstitial pick-up.
Densification modeling of titanium alloy powder during hot isostatic pressing  [PDF]
Xue Y.,Lang L.H.,Bu G.L.,Li L.
Science of Sintering , 2011, DOI: 10.2298/sos1103247x
Abstract: Densification model of titanium alloy (Ti-6Al-4V) are investigated during hot isostatic pressing (Hip). Experimental data was obtained at various pressures and temperatures during hot isostatic pressing (Hip). Experimental data are compared with the finite element calculations by using the hybrid model and Abouaf model, respectively. The results show that the finite element calculation results by the hybrid model are in agreement with the experimental data for densification behaviour of the titanium alloy powder under Hip; however, the finite element calculation results by using the Abouaf model are over the experimental data. In addition, in order to obtaining relative density distributions of porous body, the statistical relationships during Poisson’s ratio, Rockwell hardness and the relative density of porous body were formulated, the results show that the statistical relationship between Poisson’s ratio and the relative density of porous body is essential to construct such a constitutive model; the statistical relationship between Rockwell hardness and the relative density of porous body is essential to obtain relative density distributions of porous body.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.