• 한국분말재료학회지
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• 제12권3호
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• pp.174-178
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• 2005

This paper deals with the fabrication of titanium carbide using fine titanium hydride. The ratio of $TiH_2$ and C (Activated carbon) was 1:1 (mol) and milled in a planetary ball mill at a ball-to-powder weight ratio of 20:1. Thereafter, TGA was performed at $1400^{\circ}C$ to observe change of weight with milling time. Titanium carbide was obtained by using tempering the milled powders at $1100-1500^{\circ}C$. The microstructures of titanium carbide as well as the change of the lattice parameters and particle size have been studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM).

• 대한기계학회논문집A
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• 제24권12호
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• pp.3061-3071
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• 2000

Densification behavior of titanium alloy powder was investigated under hot pressing at various pressures and temperatures. Experimental date were obtained for densification of titanium alloy powder under an instantaneous loading and subsequent creep deformation during hot pressing. The constitutive models of Fleck et al. and the modified Gurson were employed for thermo-phastic deformation under the instantaneous loading and that f Abouaf and co-workers for creep deformation of titanium alloy powder during hot pressing. By implementing these constitutive equations into a finite element program(ABAQUS), finite element results were compared with experimental data during hot pressing. To investigate the effect of friction between the power and die wall, density distributions of power compacts were measured and compared with finite element calculations. Finite element results from the models of Fleck et al. and the modified Gurson agreed reasonably good with experimental data for densification and density distribution of titanium alloy powder under the instantaneous loading during hot pressing. Finite element results from the model of Abouaf and co-workers, however, somewhat overestimate experimental data for creep deformation of power compacts during hot pressing.

• 한국재료학회지
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• 제14권12호
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• pp.857-862
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• 2004

Production of titanium powder directly from tantalum oxides ($TiO_2$) pellet through an electronically mediated reaction (EMR) by calciothermic reduction has been investigated. Feed material ($TiO_2\;pellet$) and reductant (Ca-Ni alloy) were charged into electronically isolated locations in a molten calcium chloride ($CaCl_2$) bath at $950^{\circ}C$. The current flow through an external circuit between the feed (cathode) and reductant (anode) locations was monitored during the reduction of $TiO_2$. The current approximately 3.2A was measured during the reaction in the external circuit connecting cathode and anode location. After the reduction experiment, pure titanium powder with low nickel content was obtained even though Ca-Ni alloy was used as a reductant. These results demonstrate that titanium powder can be produced without direct physical contact between the feed and reductant. In certain experimental conditions, pure titanium powder with approximately $99.5\;mass\%$ purity was successfully obtained.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.274-275
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• 2006

The sintering behavior of titanium-titanium nitride nanocomposite powders has been studied by dilatometry. Titanium. titanium nitride nanocomposite powders were produced by the reactive milling of micron sized titanium powder $(12\;{\mu}m)$ in nitrogen atmosphere. The Ti-TiN nanocomposite powders milled for various durations along with the initial micron sized Ti powders were then sintered in the temperature range of $450-1000^{\circ}C$ by a constant rate of heating $(10^{\circ}C/min)$. The linear shrinkage, shrinkage rate, activation energy for sintering and microstructure has been studied and discussed as a function of milling time.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.12-13
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• 2006

The spherical and high quality Titanium fine powder "Tilop" has been produced with gas atomization furnace, Sumitomo Titanium Corporation originally designed. Recently, a new process which can produce Ti-alloy(Ti-6Al-4V) powders by utilizing our gas atomization process, of which raw material is sponge titanium pre-mixed with alloy chips or granules has been also developed. The particle size of gas atomized Ti-alloy powder and the mechanical properties of sintered Ti-alloy compacts prepared by metal injection molding were discussed in this study.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 1996년도 추계학술강연 및 발표대회 강연 및 발표논문 초록집
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• pp.31-31
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• 1996

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.1030-1031
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• 2006

Titanium alloys and Titanium alloy-based particulate composites were synthesized using the blended elemental P/M route. First, processing conditions such as the fabrication of master alloy powder were investigated. Ti-6Al-4V, Ti-5Al-2.5Fe, Ti-6Al-2Sn-4Zr-2Mo, IMI685, IMI829, Timetal 1100 and Timetal 62S, and Ti-6Al-2Sn-4Zr-2Mo/ 10%TiB and Timetal 62S/10%TiB were then synthesized using the optimal processing conditions obtained. The microstructures and mechanical properties such as tensile strength and high cycle fatigue strength were evaluated.

• Journal of Periodontal and Implant Science
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• 제30권4호
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• pp.821-836
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• 2000

The Peri-implantitis causes inflammation of periodontal tissue and bone loss. It contaminates surface of implants. Therefore, guided bone regeneration has been used for the treatment of this disease. For the reosseointegration of the exposed surface, various mechanical and chemical methods have been used for cleaning and detoxication of implant surface. Among these methods, air-powder abrasive and oversaturated citrate are known to be most effective. However, these treatments may deform implant surface. In this research, changes of surface roughness they were examined. 10 experimental machined titanium cylinder models were fabricated to be used for control groups. Each of them was air powder abraded for 1 minute and they were named group 1. And then, group 1 were burnished with cotton pellets soaked with citrate for 30 seconds(Group 2), 1 minute(Group 3), 3 minutes(Group 4), and 5 minutes(Group 5) burnishing were applied for grouping respectively. Each group were examined with SPM, and their surface roughness were measured and analyzed. 1. Surface roughness of titanium decreased when it was air-powder abraded for 1 minute. It was statistically significant. 2. When Air-powder abraded titanium were treated with citrate for 3 minutes, Their surface roughness was the lowest. Titanium treated for 1 minute was the second lowest and 30 seconds was the third and titanium burnished for 5 minutes was the highest. 3. Surface roughness of titanium which was treated with citrate was decreased till 3 minutes, which was statistically significant. There was no statistical significance from 30 seconds to 1 minute and from 1 minute to 3 minutes, and there was statistical significance from 30 seconds to 3 minutes. 4. Oxide layer was formed when titanium is exposed to air, and it was removed when air-powder abraded. It was made when treated with citrate. It is thought that citrate treatment is necessary after the air-powder abrasion, and 1 minute is clinically and qualitatively adequate for burnishing time of citrate.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2005년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
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• pp.58-58
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• 2005

• 한국분말재료학회지
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• 제24권3호
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• pp.235-241
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• 2017

Titanium alloys have high specific strength, excellent corrosion and wear resistance, as well as high heat-resistant strength compared to conventional steel materials. As intermetallic compounds based on Ti, TiAl alloys are becoming increasingly popular in the aerospace field because these alloys have low density and high creep properties. In spite of those advantages, the low ductility at room temperature and difficult machining performance of TiAl and $Ti_3Al$ materials has limited their potential applications. Titanium powder can be used in such cases for weight and cost reduction. Herein, pre-forms of Ti-Al-xMn powder alloys are fabricated by compression forming. In this process, Ti powder is added to Al and Mn powders and compressed, and the resulting mixture is subjected to various sintering temperature and holding times. The density of the powder-sintered specimens is measured and evaluated by correlation with phase formation, Mn addition, Kirkendall void, etc. Strong Al-Mn reactions can restrain Kirkendall void formation in Ti-Al-xMn powder alloys and result in increased density of the powder alloys. The effect of Al-Mn reactions and microstructural changes as well as Mn addition on the high-temperature compression properties are also analyzed for the Ti-Al-xMn powder alloys.