http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Dongxu Tang (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Dongxu Tang,Ki-Ju Lee,Jingwen Xu,Hyung-Bong Lim,K. Park,조원승 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.3
Alumina-reinforced zirconia composites containing 0 to 30 vol% of alumina were fabricated by sintering at 1550°C for 2h in air. The effect of the Al2O3 content on the mechanical properties and microstructure of 3Y-TZP ceramics was investigated. Al2O3 acted as an inhibitor of the grain growth of 3Y-TZP. As the alumina content increased, the fracture mode changed gradually from the transgranular mode to the inter-granular mode and the Young’s modulus and hardness increased. The biaxial flexural strength also showed a slight increase with an increase in Al2O3 content, due to the grain size refinement of the ZrO2 matrix,while the fracture toughness, which was investigated by the SEVNB method, showed a contrary ten-dency. The decrement of the fracture toughness can be explained by the increase in the critical transforma-tion stress, the decrease in the volume fraction of the transformable t-ZrO2 and the increase in the tensile residual stress.
-
이기주,Dongxu Tang,K. Park,조원승 대한금속·재료학회 2010 METALS AND MATERIALS International Vol.16 No.1
Porous Y-doped (Ba,Sr)TiO3 ceramics were prepared by the spark plasma sintering of (Ba,Sr)TiO3 powders with different amounts of carbon black, and by subsequently burning out the carbon black acting as a pore precursor. The microstructure, PTCR and gas-sensing characteristics for porous Y-doped (Ba,Sr)TiO3 ceramics were investigated. Spark plasma sintered (Ba,Sr)TiO3 ceramics revealed a very fine microstructure containing submicron-sized grains with a cubic phase and revealed an increased porosity after the carbon black was burned out. As a result of reoxidation treatment, the grain size of the (Ba,Sr)TiO3 ceramics increased to a few μm and the cubic phase transformed into a tetragonal phase. The phase transformation of (Ba,Sr)TiO3ceramics was affected by grain size. The PTCR jump in the (Ba,Sr)TiO3 ceramics prepared by adding 40vol.% carbon black showed an excellent value of 4.72 × 106, which was ten times higher than the PTCR jump in (Ba,Sr)TiO3 ceramics. The electrical resistivity of the porous (Ba,Sr)TiO3 ceramics was recovered as the atmosphere changed from a reducing gas (N2) to an oxidizing gas (O2) under consecutive heating and cooling cycles.
-
카본블랙을 첨가하여 제조한 다공성 BaTiO<sub>3</sub>계 세라믹스의 미세구조 및 PTCR 특성 변화
이기주,당동욱,조원승,Lee, Ki-Ju,Tang, Dongxu,Cho, Won-Seung 한국분말야금학회 2011 한국분말재료학회지 (KPMI) Vol.18 No.1
As a pore precursor, carbon black with different content of 0 to 60 vol% were added to (Ba,Sr)$TiO_3$ powder. Porous (Ba,Sr)$TiO_3$ ceramics were prepared by pressureless sintering at $1350^{\circ}C$ for 1h under air. Effects of carbon black content on the microstructure and PTCR characteristics of porous (Ba,Sr)$TiO_3$ ceramics were investigated. The porosity of porous (Ba,Sr)$TiO_3$ ceramics increased from 6.97% to 18.22% and the grain size slightly decreased from $7.51\;{\mu}m$ to $5.96\;{\mu}m$ with increasing carbon black contents. PTCR jump of the (Ba,Sr)$TiO_3$ ceramics prepared by adding carbon black was more than $10^5$, and slightly increased with increasing carbon black. The PTCR jump in the (Ba,Sr)$TiO_3$ ceramics prepared by adding 40 vol% carbon black showed an excellent value of $9.68{\times}10^5$, which was above two times higher than that in (Ba,Sr)$TiO_3$ ceramics. These results correspond with Heywang model for the explanation of PTCR effect in (Ba,Sr)$TiO_3$ ceramics. It was considered that carbon black is an effective additive for preparing porous $BaTiO_3$ based ceramics. It is believed that newly prepared (Ba,Sr)$TiO_3$ cermics can be used for PTC thermistor.
-
치과 임플란트용 지르코니아-알루미나 복합체의 생 가공 및 경 가공 특성
임형봉,당동욱,이기주,조원승,Lim, Hyung-Bong,Tang, Dongxu,Lee, Ki-Ju,Cho, Won-Seung 한국세라믹학회 2011 한국세라믹학회지 Vol.48 No.2
The green and hard machining characteristics of dental ceramics are of great interest to dental industry. The green bodies of TZP/$Al_2O_3$ composites were prepared by the cold isostatic pressing, and machined on the CNC lathe using PCD (polycrystalline diamond) insert under various machining conditions. With increasing nose radius of PCD insert, surface roughness initially increased due to increased cutting resistance, but decreased by the onset of sliding fracture. The lowest surface roughness was obtained at spindle speed of 1,300 rpm and lowest feed rate. Hard bodies were prepared by pressureless sintering the machined green bodies at several temperatures. The grinding test for sintered hard body was conducted using electroplated diamond bur with different grit sizes. During grinding, grain pull out in the composite was occurred due to thermal expansion mismatch between the alumina and zirconia. The strength of the composite decreased with alumina contents, due to increased surface roughness and high monoclinic phase transformed during grinding process. The final polished samples represented high strength by the elimination of a phase transformation layer.
ScienceON
코리아스칼라연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
