Fe-Al 계의 금속간화합물의 성장과 소멸에 관한 속도론적 연구

학위논문(박사) - 한국과학기술원 : 재료공학과, 1980.2, [ xiii, 201 p. ]The growth kinetics of intermetallic compound alloy phases between Fe-Al system were studied employing hot-dipping processes and annealing treatment of diffusion couples of various species of materials of the system. The growth of intermetallic phases was analyzed by an optical microscope and identified by X-ray diffractometer and electron probe microanalyzer. The major phase developed, in hot-dipping process, was $Fe_2Al_5(\eta)$. The growth of other thermodynamically stable phases -$FeAl_2(\zeta)$ and $FeAl_3(\theta)$- were also observed in diffusion annealing experiments and hot-dipping treatment respectively. However, due to very slow growth rate of $FeAl_2(\zeta)$, it was not detected in hot-dip aluminizing processes. It was also found that $FeAl_3(\theta)$ dissolved in liquid aluminum in hot-dip aluminizing processes, not forming a continuous layer at the interface. The major intermediate alloy layer observed consists of parallel grains of $Fe_2Al_5(\eta)$ which was grown from the aluminum into the iron side. The serrated interface was found between the alloy phase and the iron basis. This phenomena was appeared due to the nucleation of each $Fe_2Al_5(\eta)$ grain in different time at the interface. The addition of carbon and silicon in the iron or the silicon in the aluminum bath leads to the concurrent nucleation of $Fe_2Al_5(\eta)$ grain, resulting the planar interface rather than the serrated one. The growth of the $Fe_2Al_5(\eta)$ obeyed a parabolic rate law irrespective of alloying elements in iron and aluminum. As the growth of the $Fe_2Al_5(\eta)$ was controlled by interdiffusion of iron and aluminum in the phase, chemical diffusion coefficients in $Fe_2Al_5(\eta)$ were obtained through the consideration of the flux and compound stoichiometry and the layer growth rate. The activation energy for the growth of $Fe_2Al_5(\eta)$ was found to be 31.2 Kcal/mol. The addition of carbon and silicon in the iron increased the activation energy, while silicon...한국과학기술원 : 재료공학과

건축 및 자동차용 Color Glass 제조 연속 Sputtering 기술개발

funder : 산업자원부가. 제1차년도 · Sputter Chamber 제조 · 진공 Coating Chamber 제조 - 0.5m × 1m 크기의 Color Glass 제조용 - 도달진공도 : 10-5torr - 연속 Sputter 장치제조를 위한 Gate Valve 제작 · Arc제어 고성능 Power Supply 개발 · Sputter Target 연구 · 다양한 Coloring에 대한 Soft-ware 개발나. 제2차년도 · Load Lock System 개발 · Sample 이송장치개발 · 자동조절장치개발 · 다층 Coating 기술개발 · 시제품제작 및 보완 · 자동차용 발열유리 제조기술 연구 - 투명전도체 코팅기술 연구 - 두께에 따른 발열량 조사 - 최적조건 연구 · 광학용 다층 박막제조 기술연

Computer Simulation for the Growth of Cr-nitride Formed on Electrodeposited Cr during Ion-Nitriding

The structure and composition of Cr-nitrides formed on an electroplated hard Cr layer during an ionnitriding process was analyzed, and the growth kinetics of the Cr-nitrides was examined as a function of the ion-nitriding temperature and time in order to establish a computer simulation model prediction the growth behavior of the Cr-nitride layer. The Cr-nitrides formed during the ion-nitriding at $550~770^{\circ}C$ were composed of outer CrN and inner $Cr_2$N layers. A nitrogen diffusion model in the multi-layer based on fixed grid FDM (Finite Difference Method) was applied to simulate the growth kinetics of Cr-nitride layers. By measuring the thickness of each Cr-nitride layer as a function of the ion-nitriding temperature and time, the activation energy for growth of each Cr-nitride was determined; 82.26 KJ/mol for CrN and 83.36 Kj/mol for $Cr_2$N. Further, the nitrogen diffusion constant was determined in each layer; $9.70$\times10-12</TEX> /㎡/s in CrN and $2.46$\times10-12</TEX> ㎡/s in $Cr_2$N. The simulation on the growth kinetics of Cr-nitride layers was in good agreements with the experimental results at 550~720℃

Capsylite Halogen Lamp용 반사경 표면코팅 기술개발

funder : 산업자원부● 반사경 코팅용 장치의 설계 및 제작 코팅용기 규모: 800mm(Ф)×1100mm(H) 도달 진공도: $10^{-6}$ Torr 증발방식 : 전자총증발 및 저항가열증발 부대설비 : 가스유량제어 제어기기판넬 냉각설비● 제작장치의 성능평가 배기성능 증착성능 소요전력● 반사경제작용 다층박막코팅 기초실험 다층수제어 층간두께제어 소지온도제어● 코팅층의 물성평가 및 물성향상연구 반사도측정 적외선투과율 코팅층 내후성/내광성● Capsylite Halogen Lamp 반사경 시제품 제작● 시제품성능조사 및 외산과 품질비교 및 성능향상연