http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
김승언,정희원,현용택,김성준,이용태,Kim, Seung-Eon,Jeong, Hui-Won,Hyeon, Yong-Taek,Kim, Seong-Jun,Lee, Yong-Tae 한국기계연구원 1999 硏究論文集 Vol.29 No.-
A new titanium alloy system. Ti-xFe-ySi (x,y=0-4 wt%). was designed and characterized with the point at low cost and high strength for casting applications. Fe improved room and elevated temperature mechanical properties owing to solid solution hardening and beta phase stabilization. Si yielded titanium silicides and Si addition over 1 wt% resulted in poor ductility due to coarse silicide chains at prior beta boundaries. The optimum composition was found to be Ti-4Fe-(0.5-1)Si in the viewpoint of tensile strength and ductility which are comparable to the Ti-6Al-4V. The metal-mould reaction was also examined for Ti-xFe and Ti-xSi binary alloy system. The thickness of surface reaction layer w as not affected significantly with Fe content, while it was decreased with Si content. In the Ti-4Si alloy, no reaction layer was found. The depth of surface hardening layer was about $200\mum$ regardless of the mould materials.
열간단조된 $\gamma$-TiAl 합금의 이방성에 관한 연구
이재승,박노진,김성진,김승언,오명훈,Lee, Jae-Seung,Park, No-Jin,Kim, Seong-Jin,Kim, Seung-Eon,O, Myeong-Hun 한국재료학회 2000 한국재료학회지 Vol.10 No.9
본 논문에서는 Ti-48.5at%Al-0.96at%Mo 조성을 갖는 $\gamma$-TiAl 합금은 항온 단조 및 후속 조직제어 열처리 시 발달하는 집합조직의 변화에 관해 연구하였다. 특히, 동적 재결정 후 조직제어 열처리 온도와 시간의 증가에 따라 발생하는 lamellar volume fraction 과 집합조직 변화에 주목하여 관찰하였다. 동적 재결정 후 집합조직은 ND$\perp${302) 선분과, TD$\perp${100) 및 이에 비해 상대적으로 다소 약한{111) 성분들이 발달하였으며, 열처리 온도와 시간이 증가함에 따라 lameller volume fraction 은 증가했고 동일한 성분의 집합조직도 점차 강하게 발달함을 알 수 있었다. 하지만 상온인장시험 결과는 lameller volume fraction이 증가할수록 낮은 상온 연신을 보였는데, 이는 준 층상조직을 갖는 $\gamma$-TiAl합금의 상온인장특성이 집합조직의 영향보다는 lameller volume fractio과 같은 미세조직 특성에 더욱 강하게 영향을 받기 때문인 것으로 판단된다. The texture evolution during isothermal forging and subsequent heat treatment in Ti-48.5at%Al-0.6at%Mo alloy was investigated. Especially, in the present study, research interest was focused on the interrelation between lamellar volume fraction and textures varied with the change of heat-treated time and temperature. It was found that texture components having ND┴{302) and TD$\perp${100} with minor TD$\perp${111} were developed by isothermal forging. In addition, when the followed heat-treatment time and temperature increased from $1330^{\circ}C$/10h to $1350^{\circ}C$/20h respectively, both the lamellar volume fraction and the intensity of textures mentioned above also gradually increased. However, the tensile elongation at room temperature decreased oppositely, as the lamellar volume fraction increased. These results suggested that tensile properties of $\gamma$-TiAl with the nearly lamellar microstructure at room temperature were affected more strongly by the microstructural features such as lamellar volume fraction rather than by textures.
협업 필터링과 개인 성향을 이용한 여성 의류 온라인 쇼핑몰 추천 시스템
신해란 ( Hae-ran Shin ),김승언 ( Seong-eon Kim ),박두순 ( Doo-soon Park ) 한국정보처리학회 2018 한국정보처리학회 학술대회논문집 Vol.25 No.1
최근 스마트폰의 보급률이 높아지면서 인터넷 쇼핑몰의 접근성이 용이해지고 있고 그로 인해 사용자들의 인터넷 쇼핑의 이용이 보편적이게 되었다. 그 중 여성 의류 분야는 많은 비중을 차지하고 있으며 현재도 꾸준히 성장하고 있는 추세이다. 많은 여성 소비자들은 개인의 취향에 맞는 의류들을 추천 받기를 원한다. 본 논문에서는 협업 필터링에서 발생하는 cold start 문제를 이름, 나이, 선호 스타일, 자주 사용하는 쇼핑몰 등 개인 성향을 이용하여 해결하는 협업 필터링과 개인 성향을 이용한 여성 의류 쇼핑몰 추천 시스템을 제안한다.
열간가공된 γ-TiAl 합금의 미세조직 제어 및 기계적 특성 평가
박성현 ( Sung-hyun Park ),김재권 ( Jae-kwon Kim ),김성웅 ( Seong-woong Kim ),김승언 ( Seung-eon Kim ),박노진 ( No-jin Park ),오명훈 ( Myung-hoon Oh ) 한국열처리공학회 2019 熱處理工學會誌 Vol.32 No.6
The microstructural features and texture development by both hot rolling and hot forging in γ-TiAl alloy were investigated. In addition, additional heat treatment after hot forging was conducted to recognize change of the microstructure and texture evolution. The obtained microstructural features through dynamic recrystallization after hot deformed γ-TiAl were quite different because two kinds of formation process were occurred depending on deformation condition. However, analyzed texture tends to be random orientation due to intermediate annealing up to α+β region during the hot deformation process. After additional heat treatment, microstructure transformed into fully lamellar microstructure and randomly oriented texture was also observed due to the same reason as before. Tensile test at room temperature demonstrated that anisotropy of mechanical properties were not appeared and transgranular fracture was occurred between interface of α2/γ. As a result, it could be suggested that microstructural features influenced much more than texture development on mechanical properties at room temperature. (Received October 22, 2019; Revised October 31, 2019; Accepted November 4, 2019)
Ti40Zr10Cu36Pd14 비정질기지 복합재의 미세조직과 기계적 특성에 미치는 냉각속도의 영향
박선용 ( Seon Yong Park ),임가람 ( Ka Ram Lim ),나영상 ( Young Sang Na ),김승언 ( Seong Eon Kim ),최윤석 ( Youn Suk Choi ) 대한금속ㆍ재료학회 2016 대한금속·재료학회지 Vol.54 No.11
In this paper, we demonstrate that the microstructure and mechanical properties in the Ti<sub>40</sub>Zr<sub>10</sub>Cu<sub>36</sub>Pd<sub>14</sub> alloy can be tailored by controlling the cooling rate during solidification. A lower cooling rate increases the volume fraction of crystalline phase such as B2 but decreases the free volume of the glassy matrix. The increase of the B2 volume fraction can dramatically enhance the toughness of the composites, since the B2 phase is relatively ductile compared to the glassy matrix and seems to have good interface stability with the matrix. From the experimental results, it was found that there is a transition point in the plasticity of the composites depending on the cooling rate. Here, we explain how the toughness of the composites varies in accordance with the cooling rate in the Ti<sub>40</sub>Zr<sub>10</sub>Cu<sub>36</sub>Pd<sub>14</sub> alloy system. (Received April 22, 2016; Accepted May 25, 2016)
TiAl-Nb 합금의 고온상변태와 일방향응고에 관한 연구
박종문 ( Jong-moon Park ),장호승 ( Ho-seung Jang ),김성웅 ( Seong-woong Kim ),김승언 ( Seung-eon Kim ),손지하 ( Je-ha Shon ),오명훈 ( Myung-hoon Oh ) 한국열처리공학회 2016 熱處理工學會誌 Vol.29 No.5
Phase transformation phenomenon at high temperature was investigated by using designed TiAl-Nb alloys with addition of the β stabilizer. Examination of dendritic morphologies in arc-melted button ingot could reveal the crystallography of the primary solidification phase. It was found that the addition of β stabilizer(Nb) shifted the high temperature region of the binary Ti-Al phase diagram to the high Al composition side so that β phase forms as a primary crystal even at higher Al composition compared with the binary Ti-Al system. The β was found to be the primary solidification phase for alloys with Al content less than about 52 at.%. The composition of β solidification in Ti-Al-Nb ternary system could be determined from the partial liquidus projection which was constructed by observing the microstructure of arc-melted buttons. The Ti-46Al-(6, 8)Nb composition was selected for β solidification and the directional solidification was performed by a floating zone-type DS apparatus at the growth rate 30 mm/hr respectively. (Received August 12, 2016; Revised August 30, 2016; Accepted September 9, 2016)