서지주요정보
Y-Ba-Cu-O계 고온 초전도체의 spray roasting에 의한분말 제조와 sinter-forging 공정에 관한 연구 = A study on the power preparation by spray roasting and sinter-forging process of superconducting Y-Ba-Cu-O system
서명 / 저자 Y-Ba-Cu-O계 고온 초전도체의 spray roasting에 의한분말 제조와 sinter-forging 공정에 관한 연구 = A study on the power preparation by spray roasting and sinter-forging process of superconducting Y-Ba-Cu-O system / 조두희.
저자명 조두희 ; Cho, Doo-Hi
발행사항 [서울 : 한국과학기술원, 1989].
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소장정보

등록번호

4105585

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 8932

SMS전송

도서상태

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반납예정일

초록정보

Sinter-forging process was studied for the production of sintered $YBa_2Cu_3O_x$ superconductor having high Jc. And the effect of applied uniaxial stress, temperature, and sinter-forging time on the sintering behavior, microstructural variation, and Jc have been studied. Also, powder was prepared by spray-roasting with feed solution of nitrates in order to eliminate the source of carbon which is harmful to Jc. Spray-roasting powder was calcined more rapidly than the mixture of $Y_2O_3$, $BaCO_3$, and CuO powders. It is observed that the application of relatively small uniaxial stress (2MPa) produced increase in the sintered density by 15% compared with pressureless sintering. The shear deformation and sintered density increase with temperature, an enhancement of grain alignment was accompanied. Liquid phase was formed at 900°C and the presence of liquid phase largely enhanced densification and grain alignment. The transport critical current densities (Jc) of sinter-forged $YBa_2Cu_3O_x$ superconductors were between 360-420 A/$cm^2$. These Jc values were much higher than that of pressureless sintered specimens which were made of powders prepared by solid state reaction. It can be suggested the spray-roasting and sinter-forging were effective to increase Jc of $YBa_2Cu_3O_x$ superconductors. It is well known that liquid phase was harmful to Jc. However, Jc of samples sinter-forged at 90°C were higher than that of 880°C in spite of the presence of liquid phase. It is supposed that the Jc increasing effect of grain alignment overwhelmed the Jc lowering effect of liquid phase.

서지기타정보

서지기타정보
청구기호 {MMS 8932
형태사항 [iii], 56 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Doo-Hi Cho
지도교수의 한글표기 : 김종희
지도교수의 영문표기 : Chong-Hee Kim
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 53-56
주제 Superconductors.
Sintering.
Forging.
Critical currents.
초전도체. --과학기술용어시소러스
분말 제조. --과학기술용어시소러스
소결 단조. --과학기술용어시소러스
임계 전류. --과학기술용어시소러스
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