서지주요정보
Effect of MgO addition on interface structure and grain growth in alumina-anorthite = Alumina-anorthite 계에서 MgO 첨가가 계면 구조와 입자성장에 미치는 영향
서명 / 저자 Effect of MgO addition on interface structure and grain growth in alumina-anorthite = Alumina-anorthite 계에서 MgO 첨가가 계면 구조와 입자성장에 미치는 영향 / Mi-Jin Kim.
저자명 Kim, Mi-Jin ; 김미진
발행사항 [대전 : 한국과학기술원, 2001].
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등록번호

8011785

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 01006

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초록정보

Part I Alumina grain with anorthite liquid has polyhedral shape with atomically flat structure. Therefore grains are expected to grow by defect-associated process and two-dimensional nucleation. To examine the relation between growth velocity and supersaturation, sapphire single crystals with (0001) faces are embedded into alumina-15-wt% anorthite powder. The growth of basal plane of sapphire is not continuous. At high supersaturation kinetic roughening occurs. Thus the growth rate is proportional to the supersaturation and does not depend on the dislocation densities of basal planes. As lowering the supersaturation, increasing the heat treatment time, the growth rate decreases depending on the dislocation density of each basal plane. This growth behavior is consistent with step growth mechanism and leads to abnormal grain growth Part II Alumina with 5-wt% anorthite sintered at 1620℃ for 48 h shows faceted grains with flat singular surfaces in contact with liquid pools at the grain triple junctions when observed under TEM. When this specimen is heat-treated again at the same temperature after packing in MgO powder, such singular grain surfaces as the $\{1bar{01}2\}$ and {0001} planes remain, but some grain surfaces with probably high index orientations are curved. Thus the MgO addition appears to cause the roughening of edges and corners of the equilibrium shape of alumina grains in anorthite liquid and hence reduce the step free energy of the singular surfaces. This surface change resembles surface roughening transition and produces a drastic effect on grain coarsening behavior.

서지기타정보

서지기타정보
청구기호 {MMS 01006
형태사항 iii, 52 p. : 삽도 ; 26 cm
언어 영어
일반주기 저자명의 한글표기 : 김미진
지도교수의 영문표기 : Duk-Yong Yoon
지도교수의 한글표기 : 윤덕용
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 Reference : p. 34-38
주제 alumina
liquid phase sintering
abnormal grain growth
lateral growth
roughening transition
알루미나
액상소결
비정상 입자성장
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