• 청정기술
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• 제19권2호
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• pp.75-83
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• 2013

본 총설에서는 이원계 티타늄 합금 스크랩을 재활용하기 위해 수소 플라즈마 아크 용해를 이용하여 잉곳을 제조하고, 수소화-탈수소화법과 고상탈산 공정을 통해 저산소 합금 분말을 제조하는 기술에 대하여 소개하고자 한다. 이에 더해, 이원계 티타늄 합금 스크랩을 이용하여 고용상 서메트용 탄화물 분말을 제조하는 응용 분야에 대해서도 소개하고자 한다. 이원계 티타늄 합금 스크랩은 수소 플라즈마 아크 용해를 통해 건전한 잉곳의 제조가 가능함을 확인하였고, 최종적으로 제조된 티타늄 합금 분말의 산소함량은 1,000 ppm 이하였으며, 이를 고용상 서메트용 탄화물 분말의 제조에 응용이 가능함을 확인하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.209-212
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• 2001

Aircraft industry is developed very fast so titanium scrap was generated to manufacture. Titanium scrap was wasted and used to deoxidize cast iron so we are study recycling of it. In this research were studied that metal hydride of reacted in hydrogen chamber of AMS4900, 4901, return scrap titanium alloy and sponge titanium granule. The temperature of hydrogenation was 40$0^{\circ}C$ in the case of pure sponge titanium but return scrap titanium alloy were step reaction temperature at 40$0^{\circ}C$ and 50$0^{\circ}C$, and after the hydride of titanium alloy were crushed by ball mill for 5h. Titanium hydride contains to 4wt.% of hydrogen theoretically as theory. It was determined by heating and cooling curve in reaction chamber. The result of XRD was titanium hydride peak only that it was similar to pure titanium. Titanium hydride Powder particle size was about 45${\mu}{\textrm}{m}$, and recovery ratio was 95w% compared with scrap weight for a aluminum foam agent.

• 구강회복응용과학지
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• 제22권3호
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• pp.203-210
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• 2006

Although porcelain fused to metal crowns made from non-precious metal have good mechanical properties, they also have disadvantages such as the poor biological acceptability and the low corrosional resistance. Titanium is used as the alternative metal for porcelain fused to metal crowns, in spite of difficulties in casting. For that reason non-precious alloy including titanium which is easy to cast is currently used. This study evaluated the bond strength between non-precious alloy including titanium and Ni-Cr alloy. $Tilite^{(R)}V$ as non-precious alloy including titanium, $Rexilium^{(R)}V$ as Ni-Cr alloy and $Omega900^{(R)}$ and $Vintage(Regular)^{(R)}$ as porcelain powders were used. The results were as follows. 1. In comparison with the kind of alloy, the bond strength of $Tilite^{(R)}V$ was lower than that of $Rexilium^{(R)}V$. There was no significant difference between two groups. 2. In comparison with the kind of porcelain powder, the bond strength of $Omega900^{(R)}$ was higher than that of $Vintage(Regular)^{(R)}$ in $Tilite^{(R)}V$. There was significant difference between two groups(p < 0.05).

• 한국분말재료학회지
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• 제31권4호
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• pp.318-323
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• 2024

Cemented carbide for cutting tools, which is composed of carbide as a hard phase and metallic component as a metallic phase, mainly uses cobalt as the metallic phase due to the excellent mechanical properties of cobalt. However, as the demand for machining difficult-to-machine materials such as titanium and carbon fiber-reinforced plastics has recently increased, the development of high-hardness cemented carbide is necessary and the replacement of cobalt metal with a high-hardness alloy is required. In this study, we would like to introduce high-hardness cemented carbide fabricated using nickel-tungsten alloy as the metallic phase. First, nickel-tungsten alloy powder of the composition for formation of intermetallic compound confirmed through thermodynamic calculations was synthesized, and cemented carbide was prepared through the sintering process of tungsten carbide and the synthesized alloy powder. Through evaluating the mechanical properties of high-hardness cemented carbide with the nickel-tungsten alloy binder, the possibility of producing high-hardness cemented carbide by using the alloys with high-hardness was confirmed.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.523-524
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• 2006

The $TiB_2$ dispersion strengthened copper alloy was attracted as thermal and electrical functional material for the high mechanical strength, high thermal stability and good conductivity of $TiB_2$. In the present study, the focus is on the synthesis of $TiB_2$ dispersed copper alloy by spark plasma sintering process using copper oxide and titanium diboride as raw materials. The mechanical, thermal and electrical properties of sintered bodies were discussed with the sintering parameters, and developed microstructure and phase of sintered bodies.

• 화약ㆍ발파
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• 제19권1호
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• pp.101-110
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• 2001

Depleted uranium (DU) outperforms tungsten heavy alloys (WHA) by about 10%. Because of environmental and hence, political concerns, there is a need to improve WHA performance, in order to replace the DU penetrators. A technique of metal powder compaction by the detonation of an explosive has been applied to tungsten-titanium(W-Ti) powder materials that otherwise may be difficult to fabricate conventionally or have dissimilar, nonequilibrium, or unique me1astab1e substructures. However, the engineering properties of compacted materials are not widely reported and are little known especially for the "unique" composition of W-Ti alloy. To develop high-performance tungsten composites with superior ballistic attributes, it is necessary to understand, carefully document controlled experimental results, and develop basic computational models for potential composites with controlled microstructures. A detailed understanding and engineering application of W-Ti alloy can lead to the development of new structural design for engineering components and materials.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.540-541
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• 2006

SUS316L stainless steel, commercial pure Titanium and Ti-6Al-4V alloy powders applied by Mechanical Milling (MM) process are sintered by Hot Roll Sintering (HRS) process. Microstructure and mechanical properties of those HRS materials is investigated. The microstructures of materials produced by HRS process consist of fine grains and work-hardened structure, that is, the hybrid microstructure. Tensile test of the HRS material demonstrated the good mechanical properties. These results show that the HRS process is very effective to the improvement of mechanical properties in the SUS316L stainless steel, commercial pure Titanium and Ti-6Al-4V alloy.

• 한국재료학회지
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• 제33권6호
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• pp.242-250
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• 2023

Titanium, which has excellent strength and toughness characteristics, is increasingly used in the aerospace field. Among the titanium alloys used for body parts, more than 80 % are Ti-6Al-4V alloys with a tensile strength of 931 MPa. The spark plasma sintering (SPS) method is used for solidification molding of powder manufactured by the mechanical milling (MM) method, by sintering at low temperature for a short time. This sintering method avoids coarsening of the fine crystal grains or dispersed particles of the MM powder. To improve the mechanical properties of pure titanium without adding alloying elements, stearic acid was added to pure titanium powder as a process control agent (PCA), and MM treatment was performed. The properties of the MM powder and SPS material produced by solidifying the powder were investigated by hardness measurement, X-ray diffraction, density measurement and structure observation. The processing deformation of the pure titanium powder depends on the amount of stearic acid added and the MM treatment time. TiN was also generated in powder treated by MM 8 h with 0.50 g of added stearic acid, and the hardness of the powder was higher than that of Ti-6Al-4V alloy when treated with MM for 8 h. When the MM-treated powder was solidified in the SPS equipment, TiC was formed by the solid phase reaction. The SPS material prepared as a powder treated with MM 8 h by adding 0.50 g of stearic acid also formed TiN and exhibited the highest hardness of Hv1253.

• Archives of Metallurgy and Materials
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• 제65권3호
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• pp.997-1000
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• 2020

With the recent advancement in technology for titanium metal powder injection molding and additive manufacturing, high yield and good flowability powder production is needed. In this study, titanium powder was produced through vacuum induction melting gas atomization with a cold crucible, which can yield various alloy compositions without the need for material pretreatment. The gas behavior in the injection section was simulated according to the orifice protrusion length for effective powder production, and powder was prepared based on the simulation results. The gas distribution changes with the orifice protrusion length, which changes the location of the recirculation zone and production yield of the powder. The produced powders had a spherical morphology, and the content of impurities (N, O) changed with the injected-gas purity.

• 한국분말재료학회지
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• 제18권4호
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• pp.359-364
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• 2011

Zr-Ti alloy powders were successfully synthesized by magnesium thermal reduction of metal chlorides. The evaporated and mixed gasses of $ZrCl_4+TiCl_4$ were injected to liquid magnesium and the chloride components were reduced by magnesium leading to the formation of $MgCl_2$. The released Zr and Ti atoms were then condensed to particle forms inside the mixture of liquid magnesium and magnesium chloride, which could be dissolved fully in post process by 1~5% HCl solution at room temperature. By the fraction-control of individually injected $ZrCl_4$ and $TiCl_4$ gasses, the final compositions of produced alloy powders were changed in the ranges of Zr-0 wt.%~20 wt.%Ti and their purity and particle size were about 99.4% and the level of several micrometers, respectively.