STS 304 , 316 강의 열처리에 따른 산화거동

이경구,윤동주,기회봉,강창석,이도재 ( Kyung Ku Lee,Dong Ju Yoon,Whe Bong Ghi,Chang Sug Kang,Doh Jae Lee ) 한국열처리공학회 1998 熱處理工學會誌 Vol.11 No.3

N/A An oxidation behavior of 304 and 316 stainless steels were studied in dry air. After solution treatment, specimens were polished up to 1㎛ A1₂O₃ grade and then subjected to oxidation treatment in dry air at 800℃∼1200℃. The oxidation behavior between matrix and oxide scale was analyzed with SEM, EDS and XRD. When oxidation treatment was conducted at 1200℃, large thickness of Fe oxide scale was formed on top of surface and fine (Cr,Fe)₂O₃oxide film was formed below it. Cr rich zone existed at interface between metal and (Cr,Fe)₂O₃oxide layer, and it was believed that this zone acted as obstacle to oxidation. Most of Ni was detected at the interface between metal and (Cr,Fe)₂O₃and also detected at the interface between Fe₂O₃and (Cr,Fe)₂O₃.

Al / SiCp 복합재료에서 보강재 표면의 금속 피복층이 젖음성과 계면 강도에 미치는 영향

이경구,이도재 ( Kyung Ku Lee,Doh Jae Lee ) 한국주조공학회 1995 한국주조공학회지 Vol.15 No.4

N/A Effects of metal coating treatment on SiC particle on wetting behavior and interfacial strength were studied. Experimental variables are included types of coated metallic films such as Cu and Ni-P, and temperatures of heat-treatment under vacuum. The experimental results concerning wetting phenomena of liquid Al on SiC, showed that coating treatment of metallic film on SiC particles remarkably improves the wetting behavior of liquid Al on SiC, especially in the case of Ni-P coating. The interfacial strength of Al/SiC composites made of coated SiC plate was higher than that of the composite with non-coated SiC plate although the coating treatment was not perfect.

Squeeze Casting 법에 의해 제조된 A356 / coated SiC 복합재료의 미세조직과 기계적 특성에 관한 연구

이경구,이도재 ( Kyung Ku Lee,Doh Jae Lee ) 한국주조공학회 1994 한국주조공학회지 Vol.14 No.5

N/A Influence of interfacial structure between matrix and particle in A356/coated SiC composite fabricated by squeeze casting method was studied. Experimental variables are types of coated metallic film on SiC particles such as Cu, Ni-P, and applied pressure for squeeze casting. It was found that coating treatment on SiC particles improves the wetting of liquid A356 alloy on SiC particles. SiC particle distribution is very homogeneous in A356 matrix alloy which is fabricated by squeeze casting. Analysing the surface morphology of fractured A356/coated SiC, it was concluded that metallic thin film by coating treatment on SiC particle improves the interfacial bonding between particle and matrix, and so does on mechanical properties such as tensile strength. However, there was on significant difference in hardness between those composite made of as-received SiC particle and coated SiC particle.

PFC 법에 있어서의 Al-Cu 다결정리본의 응고특성

이경구,이상목,홍준표 ( Kyung Ku Lee,Sang Mok Lee,Chun Pyo Hong ) 한국주조공학회 1995 한국주조공학회지 Vol.15 No.4

N/A Polycrystalline Al-Cu ribbons were produced by planar flow casting(PFC). Solidification behavior and microstructual changes of the ribbons have been investigated as a function of ribbon thickness and processing parameters. The solidification front velocity, V varies within the ribbon, decreasing with increasing the distance, S from the wheel-contact surface, as V=17.6S^(-1). In Al-4.5wt%Cu alloy, rapid decrease in solidification velocity toward the free surface causes a change in solidification morphology from planar to cellular, and finally, to dendritic. The length and inclination of columnar grains solidified with planar front were related to the wheel velocity. The transition from particulate degenerate eutectic structure to regular lamellar eutectic structure was observed to be caused by a difference of the relative growth velocites of α-Al and θ during solidification in the Al-Cu eutectic alloy.

가압주조법에 의해 제조된 AC4C Al / coated SiC 복합재료의 마모특성에 관한 연구

이경구,이도재 ( Kyung Ku Lee,Doh Jae Lee ) 한국주조공학회 1996 한국주조공학회지 Vol.16 No.4

N/A Effects of SiC particle on wear resistance of AC4C Al/SiC composite were studied. Experimental variables included were types of metallic coatings such as Cu and Ni-P, and volume fraction of SiC particle in composite. The results of wear test showed that the wear resistance of AC4C Al/SiC composite is increased linearly with volume fraction of SiC particles. In the range of our experimental conditions, there is no significant difference in wear resistance between the type of pretreatment for coating on SiC particles used for composite specimens the as-received SiC reinforced and coated SiC reinforced composite. Wear debries generated during wear test are identified as Al from matrix alloy of specimen, and iron oxide from steel block which is counter part of abrasion test. Severe subsurface plastic deformation is observed at the regions close to the wear surface, and the surface region were work hardened.

19세기 전반 민, 지식인, 문자관에 대한 시론

이경구 ( Kyung Ku Lee ) 한림과학원 2013 개념과 소통 Vol.0 No.12

19세기 전반에 조선은 이질적인 현상의 병존이 두드러졌다. 국가의 신축성이 쇠퇴하고 사상 통제가 심해진 반면, 민의 움직임은 이전보다 활발해졌고 정보와 지식의 총합은 늘어났다. 본고는 이 같은 현상에 대한 최근의 주목할 만한 연구를 검토하면서 시작하였다. 검토를 통해 일탈적 지식인의 역할이 민의 성장에 일정한 계기를 부여하였음을 지적하였다. 이어 19세기 전반기의 주변적 지식인에 대해 실험적으로 유형화를 시도하였다. 그 결과 일상, 전문세계에 침잠하거나 중국과의 문화 혼종을 강조하거나, 새로운 지식체계를 고민하는 경향 등을 주목할 수 있었다. 마지막으로 상대적으로 지속성이 강한문자에 대한 인식을 검토하였다. 문자관은 18세기 후반과 크게 다르지 않았고 한문·유교문화의 구심력이 여전하였음을 보여 준다. The early part of the 19th century was a time of marked contrasts in Joseon. While the state gradually hardened, and the censorship of thought became more aggressive, its people began to express themselves with ever more vitality in response to the accumulating flood of information and knowledge which was entering the country. This essay reviews the relevant research which has been carried out so far to analyze the complexity of the 19th century, and highlights the contribution made by some liberal intellectuals. There follows a more specific examination of some intellectuals at the periphery, in which three types or categories can be tentatively recognized:first, there were some intellectuals who withdrew into their own private or specialized world;second, there were some who emphasized the Confucian cultural continuity between Joseon and China; and third, there were others who were groping for a new system of thought, or a new value system. Finally, I examine the general assessment of character, finding it to be relatively stable and persistent. The fact that the 19th century view of what constituted a good or bad character differed little from that of the late 18th century shows that the centripetal force of Confucian culture was still powerful.

논문(論文) : 18세기 "時"와 "俗" 관련 용어의 변화와 그 의미

이경구 ( Kyung Ku Lee ) 한국실학학회 2008 한국실학연구 Vol.15 No.-

개념사와 내재적 발전

이경구(Lee Kyung-Ku) 역사학회 2012 역사학보 Vol.0 No.213

A common paradigm underpins both autochthonous development theory, which aims at establishing a concept of developmental history by picking out aspects of Western modernity in Korean history and Korean conceptual history, which tries to settle the modern Western order in Korea by accepting Western concepts. This paradigm, however, is now facing criticism that it will end up intensifying the dichotomy of ‘West vs. East’. The conceptual history of Silhak(實學) however can let us move beyond this paradigm. Silhak as a concept demonstrating autochthonous development, has changed in usage and meaning. Traditionally, it mainly referred to the study of Confucian classics in preparation for Gwageo(科擧), or the academic study of Confucianism during the Joseon Dynasty period. After having undergone a transition of meaning in the 19th century, it came to have its current meaning after the 1960s. The intent of the change in meaning was to connect a new academic inclination in the 18th century under the mottos of ‘institutional approach to government(經世致用)’ and ‘economic enrichment(利用厚生)’ with modernity. It was also to combine pre-modern content with modern form. This combination is applicable to the embryonic theory of capitalism, another main axis of the autochthonous development theory. Once free from the paradigm of Western-style capitalism, we can examine the embryo of Eastern-style modernity on a broad scale.

이영훈 외 지음 『반일 종족주의 (反日 種族主義)』를 읽고서

이경구(Lee Kyung-ku) 한국외교협회 2020 계간 외교 Vol.- No.132

영조 순조 연간 호락논쟁의 전개

이경구 (Kyung Ku Lee) 일지사 1998 韓國學報 Vol.24 No.4

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