http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
논문 : 분말야금 ; 고속 충돌된 텅스텐 중합금의 미세조직 변화
김은표 ( Eun Pyo Kim ),송흥섭 ( Heung Sub Song ),문인형 ( In Hyung Moon ) 대한금속재료학회 ( 구 대한금속학회 ) 1998 대한금속·재료학회지 Vol.36 No.6
Microstructural change in 93W-4.9Ni-2.1Fe heavy alloy was investigated by metallurgical analyses of the fragments from penetrators after high speed impact test. Two kinds of specimens were prepared. The one was normal specimen manufactured by a typical liquid phase sintering process, and the other was the D specimen made by a double-cycle sintering process, respectively. The morphology of tungsten grain in the D specimen became irregular by the double-cycle sintering. And microstructural changes observed from the fragments after the test were local deformation in W grain and matrix phase, fracture, formation of adiabatic shear band, reaction with steel target and so on, irrespective of the specimens. However, fracture mode was changed from W-W and W-matrix interface to W cleavage when W grains became irregular, by which the penetrator could be more brittle and fragile. From the analyses, it was suggested that the microstructural change in tungsten grain and formation of inhomogeneous matrix band would be beneficial for the self sharpening effect.
W-Ni-Fe 중합금의 미세조직 변화에 대한 μ-phase의 영향
김대건,김은표,김영도,Kim, Dae-Geon,Kim, Eun-Pyo,Kim, Yeong-Do 한국재료학회 2002 한국재료학회지 Vol.12 No.1
In this study, the 95W heavy alloys of 3/7, 5/5 and 7/3 of Ni/Fe ratio were sintered at the temperature range between 1420 and $1480^{\circ}C$ for 1h and their microstructures were discussed for an effect of the ${\mu}$-phase $(Fe_7W_6)$ on the microstructure. The ${\mu}$-phase was observed in the only 95W-1.5Ni-3.5Fe alloy of 3/7 and it is thought to be formed and grown from the surface of the W particle. The W particle was surrounded with the ${\mu}$-phase and there were only the W particles and this phase without Ni-Fe-W matrix at the most part. The ${\mu}$-phase changed the interphase structure in the alloy and the grain growth of the W was suppressed because of interrupting the solution-reprecipitation of the W. The W content in the matrix was considered to be lowered due to the interruption of the solution-reprecipitation and the formation of the ${\mu}$-phase in the .
김영무,김은표,이성,노준웅,Kim, Young-Moo,Kim, Eun-Pyo,Lee, Seong,Noh, Joon-Woong 한국분말야금학회 2007 한국분말재료학회지 (KPMI) Vol.14 No.4
이상에서 살펴본 바와 같이, 내열재료들은 고밀도를 이용하여 비행하는 물체의 운동에너지를 극대화 시킬 수 있기 때문에 군사적으로 각종 무기체계의 성능 향상에 매우 중요하다. 또한 유도 무기 및 항공기의 경우 고온, 고압 등의 환경에서 운용되기 때문에, 이러한 조건에서 견딜 수 있는 소재 개발이 필수적이다. 따라서 무기 선진국에서는 고밀도 재료인 텅스텐, 몰리브덴, 탄탈륨, 텅스텐-구리 감손우라늄을 활용하기 위한 연구를 활발하게 진행하고 있다. 이중, 텅스텐, 몰리브덴, 텅스텐-구리 라이너에 관한 연구는 괄목할 만한 연구 성과를 거두고 있다. 이러한 연구성과는 기존 탄의 관통 성능을 크게 증가시켜, 이에 대응하고자 하는 방어 체계 연구자들을 바쁘게 할 것으로 판단된다. 한편 내열 금속의 경우, 초고온 및 고압과 같은 극한 환경에서의 고온 강도 및 내삭마성이 우수하기 때문에, 각종 유도 무기 체계의 구성 부품, 즉 터빈, 밸브, 노즐, 제트 베인 등에 적용되고 있으나 대부분의 내열 재료들은 제조 방법이 까다롭고, 가공성이 나쁘며, 고가라는 단점들이 있어 이를 극복하는 연구들이 현재 진행 중에 있다.
송흥섭,김은표,박경진,류주하,Song Heung Sub,Kim Eun Pyo,Park Kyung Jin,You Joo Ha 한국분말야금학회 2004 한국분말재료학회지 (KPMI) Vol.11 No.5
A new concept of tungsten heavy alloy composite was suggested and manufactured in this study for the kinetic energy penetrator. The composite heavy alloy was composed of two parts, the center was molybdenum added heavy alloy compositions which were designed to promote the self-sharpening effect and outside was conventional heavy alloy in order to sustain the severe stress condition in the muzzle during the firing. The center part showed an intergranular and brittle mode at tungsten/tungsten interfaces by which self-sharpening effect could be activated. On the other hand, that of outside showed conventional ductile fracture mode under high strain rate condition. From the sub-scale penetration test, the depth of penetration in heavy alloy composites showed greater values than those of conventional tungsten heavy alloys. It is suggested that the heavy alloy composite could be considered as one of the future penetrator materials.
열간 등압 성형된 니켈기 초내열 합금 IN 713C 분말 소결체의 특성 평가
김영무,김은표,정성택,이성,노준웅,이성호,권영삼,Kim, Youngmoo,Kim, Eun-Pyo,Chunga, Seong-Taek,Lee, Seong,Noh, Joon-Woong,Lee, Sung Ho,Kwon, Young-Sam 한국분말야금학회 2013 한국분말재료학회지 (KPMI) Vol.20 No.4
Nickel-based superalloy IN 713C powders have been consolidated by hot isostatic pressing (HIPing). The microstructure and mechanical properties of the superalloys were investigated at the HIPing temperature ranging from $1030^{\circ}C$ to $1230^{\circ}C$. When the IN 713C powder was heated above ${\gamma}^{\prime}$ solvus temperature (about $1180^{\circ}C$), the microstructure was composed of the austenitic FCC matrix phase ${\gamma}$ plus a variety of secondary phases, such as ${\gamma}^{\prime}$ precipitates in ${\gamma}$ matrix and MC carbides at grain boundaries. The yield and tensile strengths of HIPed specimens at room temperature were decreased while the elongation and reduction of area were increased as the processing temperature increased. At $700^{\circ}C$, the strength was similar regardless of HIPing temperature; however, the ductility was drastically increased with increasing the temperature. It is considered that these properties compared to those of cast products are originated from the homogeneity of microstructure obtained from a PM process.
이성,홍문희,김은표,이성호,노준웅,Lee, Seong,Hong, Moon-Hee,Kim, Eun-Pyo,Lee, Sung-Ho,Noh, Joon-Woong 한국분말야금학회 2003 한국분말재료학회지 (KPMI) Vol.10 No.6
The reduction mechanism of the composite powders mixed with $WO_3$ and CuO has been studied by using thermogravimetry (TG), X-ray diffraction, and microstructure analyses. The composite powders were made by simple Turbula mixing, spray drying, and ball-milling in a stainless steel jar with the ball to powder ratio of 32 to 1 at 80 rpm for 1 h without process controlling agents. It is observed that all the oxide composite powders are converted to W-coated Cu composite powder after reducing treatment under hydrogen atmosphere. For the formation mechanism of W-coated Cu composite powder, the sequential reduction steps are proposed as follows: CuO contained in the ball-milled composite powder is initially reduced to Cu at the temperature range from 20$0^{\circ}C$ to 30$0^{\circ}C$. Then, $WO_3$ powder is reduced to W $O_2$ via W $O_{2.9}$ and W $O_{2.72}$ at higher temperature region. Finally, the gaseous phase of $WO_3(OH)_2$ formed by reaction of $WO_2$ with water vapour migrates to previously reduced Cu and deposits on it as W reduced by hydrogen. The proposed mechanism has been proved through the model experiment which was performed by using Cu plate and $WO_3$ powder.
정재연(Jung, Jae Yeon),김은표(Kim, Eun Pyo),남석인(Nam, Seok In) 한국노인복지학회 2021 노인복지연구 Vol.76 No.4
최근 국내외적으로 노인의 주거와 관련하여 지역사회계속거주(AIP)와 커뮤니티케어 정책이 중요시되고 있다. 본 연구는 노년기 지역사회계속거주의 주요한 요인을 주거환경과 이웃 관계의 건강함에 주목하였다. 이를 위해 ‘2019년 주거실태조사’를 활용하여 잠재프로파일분석을 실시하였다. 노인의 삶에 영향을 주는 주거환경 만족 유형으로 시설 · 서비스 불만족, 시설 불만족 · 서비스 만족, 시설 만족 · 서비스 불만족, 시설 · 서비스 높은 만족의 4가지 유형을 도출하였다. 도출된 유형으로 다항 로지스틱 회귀분석과 다중회귀분석을 실시하여 유형의 특성 및 영역 간의 상호 연관성, 유형별 이웃관계에 대한 영향을 확인하였다. 주거환경의 시설 또는 서비스 영역 중 하나라도 만족하면 이웃관계에 긍정적인 영향을 주는 것으로 나타났다. 이러한 연구결과를 바탕으로 지역사회계속거주를 위한 커뮤니티케어 기반 주거환경 개선과 노인의 건강한 이웃관계에 대한 정책적 · 실천적 방안을 제시하였다. Recently, Aging In Place(AIP) and Community care policies have become important concerning the housing of older people. This study focused on the residential environment and neighborhood relationships as the main factors of Aging In Place(AIP) in old age. We conducted a latent profile analysis using the ‘2019 Korea Housing Survey to analyze the types of residential environment satisfaction. Four types of residential environment satisfaction were derived: the ‘facility and service dissatisfaction’, the ‘facility dissatisfaction and service satisfaction’, the ‘facility satisfaction and service dissatisfaction’, and the ‘facility and service high satisfaction’. In addition, Multinomial logistic regression analysis and multiple regression analysis were conducted with the derived types to confirm the characteristics of the type and the effect on neighborhood relationships by type. It was found that if any one of the facilities or service areas of the residential environment was satisfied, it had a positive effect on neighborhood relationships. Based on these results, we propose policy and practical intervention strategies for the improvement of the residential environment based on community care and the healthy neighborhood relationships of older people.