라인스캔 카메라를 이용한 현미의 온라인 품위판정 시스템 개발

학위논문(석사)--서울대학교 대학원 :농공학과 농업기계전공,1999.Maste

Low Temperature Mechanical Properties and Microstructures of Cryogenic Fe-30Mn-12Cr-xAl Alloys

The effects of Al addition (0-3wt%) to Fe-30Mn-12Cr-xAl cryogenic alloys on tensile properties and microstructures were investigated within temperature ranged from -196℃ to 25℃. The addition of Al increased the stability of δ-ferrite and Fe-30Mn-12Cr-3Al alloy showed the phase transition from single γ phase to γ plus δ-ferrite. The Fe-30Mn-12Cr-0Al alloy showed the deformation induced ε-martensite in deformed structure at -196℃. The deformation twins were observed in deformed cryogenic alloys except Fe-30Mn-12Cr-2Al alloy, in which the stacking fault energy of γ phase exceed about 50mJ/㎡. The formation of deformation twins during the tensile test was found to be beneficial to enhance the elongation through multiple necking. Fe-30Mn-12Cr-(0, 1, 3)wt% alloys showing deformation twins exhibited the elongation peaks between -196℃ and 25℃. The elongation peak shifted to lower temperature with increased Al content, since the stacking fault energy increases with increasing Al content. The stacking fault energies of the cryogenic alloys at temperatures showing the elongation peaks were calculated to be about 35-40mJ/㎡. The gradual formation of deformation twin during the test was found to be important to maximize the elongation

Electrochemical characteristics of pyrolytic carbon (PyC) and PyC-coated graphite for active materials of anodes in Li-ion secondary batteries

학위논문(박사) - 한국과학기술원 : 재료공학과, 2000.8, [ ix, 106 p. ]한국과학기술원 : 재료공학과

The effects of Al contents on phase transformation and low temperature deformation characteristics in cryogenic Fe-(25, 30)Mn-12Cr-xAl-C alloys

학위논문(석사) - 한국과학기술원 : 재료공학과, 1994.2, [ 89 p. ]한국과학기술원 : 재료공학과

A study on the diamond synthesis by the microwave plasma CVD in the CH4/H2/Ar/O2CH_4/H_2/Ar/O_2 systems

학위논문(석사) - 한국과학기술원 : 재료공학과, 1996.2, [ iii, 52 p. ]한국과학기술원 : 재료공학과