간행물
한국분말야금학회지 KCI 등재 Journal of Korean Powder Metallurgy Institute
- 발행기관 한국분말재료학회(구 한국분말야금학회)
- 자료유형 학술지
- 간기 격월간
- ISSN 1225-7591 (Print)2287-8173 (Online)
- 수록기간 1994 ~ 2024
- 주제분류 공학 > 금속공학 공학 분류의 다른 간행물
- 십진분류KDC 559DDC 629
권호리스트/논문검색
Vol. 15 No. 6 (2008년 12월) 11건
1.
2008.12
구독 인증기관 무료, 개인회원 유료
4,000원
2.
2008.12
구독 인증기관 무료, 개인회원 유료
The objectives of this study were the development of a synthesis technique for highly active nanosized ITO powder and the understanding of the reaction mechanisms of the ITO precursors. The precipitation and agglomeration phenomena in ITO and precursors are very sensitive to reaction temperature, pH, and coexisting ion species. Excessive ion and ions had a negative effect an synthesizing highly active powders. However, with a relevant stabilizing treatment the shape and size of ITO and precursors could be controlled and high density sintered products of ITO were obtained. By applying the reprecipitation process (or stabilization technique), highly active ITO and powders were synthesized. Sintering these powders at for 5 hours produced 97% dense ITO bodies.
4,000원
3.
2008.12
구독 인증기관 무료, 개인회원 유료
The hot deformation characteristics of pure molybdenum was investigated in the temperature range of and strain rate range of using a Gleeble test machine. The power dissipation map for hot working was developed on the basis of the Dynamic Materials Model. According to the map, dynamic recrystallization (DRX) occurs in the temperature range of and the strain rate range of , which are the optimum conditions for hot working of this material. The average grain size after DRX is . The material undergoes flow instabilities at temperatures of and the strain rates of , as calculated by the continuum instability criterion.
4,000원
4.
2008.12
구독 인증기관 무료, 개인회원 유료
Experiments with a URT-0.5 accelerator (0.5 MeV, 50 ns, 1 kW) generating a nanosecond electron beam for irradiation of silver nitrate in various liquid solutions (water and toluene) were performed with the aim of producing silver nanopowders. A radiochemical reaction allows making weakly agglomerated pure Ag powders with particles of 10-15 nm and 30-50 nm in size by irradiation in toluene and water respectively. The injection of the nanosecond electron beam energy to the solution is optimal. As the absorbed dose increases, the output of the radiochemical reaction does not grow, but more agglomerated powders are synthesized.
4,000원
5.
2008.12
구독 인증기관 무료, 개인회원 유료
Microstructure Control and Magnetic Property of Nd-Fe-B Sintered Magnets After Cyclic Heat Treatment
Sintered Nd-Fe-B magnets have been widely used due to their excellent magnetic properties, especially for driving motors of hybrid and electric vehicles. The microstructure of Nd-Fe-B magnets strongly affects their magnetic properties, in particular the coercivity. Therefore, a post-sintering process like heat-treatment is required for improving the magnetic properties of Nd-Fe-B sintered magnets. In this study, cyclic heat treatment was performed at temperatures between and up to 16 cycles in order to control microstructures such as size and shape of the Nd-rich phase without grain growth of the phase. The 2 cycles specimen at this temperature range showed more homogeneous microstructure which leads to higher coercivity of 35 kOe than as-sintered one.
4,000원
6.
2008.12
구독 인증기관 무료, 개인회원 유료
Formation and characteristics of spraying powder for BSCCO High-Tc superconductor prepared by plasma spray coating were investigated. The addition of 3% of binder gives the best flowability of the powder. Ball milling for 30h and 35h gives the best flowability of powder in the case of 2001 and 0212, respectively. The withdraw ratio increases upon binder addition from 12 to 27% in the case of 2001 and from 18 to 31% in the case of 0212 for sieving powder of in size. The built-up efficiency for thickness of spray coating is increased more than 30% by binder addition. The microstructure of the spray coated layers was investigated by XRD and EDS analysis.
4,000원
7.
2008.12
구독 인증기관 무료, 개인회원 유료
The indentation technique has been one of the most commonly used techniques for the measurement of the mechanical properties of materials due to its experimental ease and speed. Recently, the scope of indentation has been enlarged down to the nanometer range through the development of instrumentations capable of continuously measuring load and displacement. In addition to testing hardness, the elastic modulus of submicron area could be measured from an indentation load-displacement (P-h) curve. In this study, the hardness values of the constituent phases in Ti()-NbC-Ni cermets were evaluated by nanoindentation. SEM observation of the indented surface was indispensable in order to separate the hardness of each constituent phase since the Ti()-based cermets have relatively inhomogeneous microstructure. The measured values of hardness using nanoindentation were GPa for hard phase and GPa for binder phase. The effect of NbC addition on hardness was not obvious in this work.
4,000원
8.
2008.12
구독 인증기관 무료, 개인회원 유료
Colored tantalum oxy-nitride (TaON) and tantalum nitride () were synthesized by ammonolysis. Oxygen deficient tantalum oxides () were produced by a titration process, using a tantalum chloride () precursor. The stirring speed and the amount of were important factors for controling the crystallinity of tantalum oxides. The high crystallinity of tantalum oxides improved the degree of nitridation which was related to the color value. Synthesized powders were characterized by XRD, SEM, TEM and Colorimeter.
4,000원
9.
2008.12
구독 인증기관 무료, 개인회원 유료
Aluminum nitride (AlN) powders were prepared by the chemical vapor synthesis (CVS) process in the system. Aluminum chloride () as the starting material was gasified in the heating chamber of . Aluminum chloride gas transported to the furnace in atmosphere at the gas flow rate of 200-400ml/min. For samples synthesized between 700 and , the XRD peaks corresponding to AlN were comparatively sharp and also showed an improvement of crystallinity with increasing the reaction temperature. In additions, the average particle size of the AlN powders decreased from 250 to 40 nm, as the reaction temperature increased.
4,000원
10.
2008.12
구독 인증기관 무료, 개인회원 유료
Ti(C,N) solid solutions in hot-pressed Ti() (x=0.0, 0.3, 0.5, 0.7, 1.0) and 40TiC-40TiN-20Ni (in wt.%) cermet were characterized in this study. For hot-pressed Ti(C,N)s, the lattice parameters and hardness values of Ti(C,N) were determined by using XRD (X-Ray Diffraction) and nanoindentation. The properties of hot-pressed Ti(C,N) samples changed linearly with their carbon or nitrogen contents. For the TiC-TiN-Ni cermet, the hardness of the hard phase and binder phase were determined by nanoindentation in conjunction with microstructural observation. The measured hardness values were GPa for the binder phase and GPa for the hard phase, which was close to the hardness of hot-pressed Ti().
4,000원
11.
2008.12
구독 인증기관 무료, 개인회원 유료
High-pressure abrasive entrained jet have rapidly become important machining technology over the last two decades. However, suspension jet by high-pressure has been recently developed for packaging sawing. Ideally, diamond materials should be used for components in abrasive water-jet systems that are subject to high erosive conditions. Using the diamond orifices improve maintenance and extend wear part life. This paper gives insights to using an abrasive suspension jet with diamond orifice. The influences of orifice material and orifice design are evaluated.
4,000원
