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Jeong, Nam-Geun
- 열병합발전
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- s.30
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- pp.21-25
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- 2002
According to recent Korea Electric Power Company report, yearly distribution line brass cramp bolts failure summed up to 4,400 cases emerging as one of main local break-down causes. Naturally, the need for the investigation was proposed To determine the root cause of the cramp bolt failures, mechanical and metallurgical investigation were performed for 90 samples which collected from various sites. For the understanding of the geometric characteristics, stress distribution was evaluated by CAE program and proof load of each bolts was tested. The SEM&EDS was used for metallurgical investigation. Through the investigation, the root causes of failures were confirmed. All damaged bolts showed intergrannular fracture mode and the all fractured bolt showed ß phase morphology contrast to the a&ß mixture morphology of the non-damaged samples. Additionally, EDS analysis confirmed the existence of lead rich layer on grain boundaries.
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Jung, Jin-Seo;Jun, Jae-Uhk;Han, Gu-Sang;Seo, Sang-Ha;Ha, Man-Kyung
- Journal of the Korean Society of Manufacturing Process Engineers
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- v.2 no.1
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- pp.39-44
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- 2003
In the present industry, there are necessary to cut not only iron metals but also non-ferrous metals such as aluminum, brass, plastic and wood(Paulownia) therefore it had been made the studies of non-ferrous metals by many scientists. The purpose of this study is to conduct the basic experiment about influencing of the feedrate adjustment and the change of the side rake angle at turning of non-ferrous metals. As the results, the surface roughnesses and Cutting force adjustments were on the decrease with a side-rake angle and feedrate diminution in the case of the plastic, brass, aluminum, and paulownia.
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전재억;정진서;최창수;하만경
- Proceedings of the Korean Society of Machine Tool Engineers Conference
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- 2001.10a
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- pp.32-37
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- 2001
In the present industry, there are necessary to cut not only iron metals but also non-ferrous metals such as aluminum, brass, plastic and wood(Paulownia). therefore it had been made the studies of non-ferrous metals by many scientists. we hope this kind of study will continue. The purpose of this study is to conduct the basic experiment about influencing of change the side rake angle at turning of non-ferrous metals. As the results, the surface roughnesses were on the increase with a increase of side-rake angle at the case of the plastic, brass, aluminum, and paulownia.
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최성영;김진수
- Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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- 1998.11a
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- pp.235-238
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- 1998
In this study, the cymbal actuators with brass and bronze endcap at various endcap thickness were fabricated, and then the displacement vs applied voltage relation and position from the center of endcap relation were investigated The displacement values of all cymbal actuator were measured using laser vibrometer. The displacement of the cymbal actuator was increased linearly with increasing applied voltage. The cymbal actuator with 0.15mm thick brass endcap show approximately 1.3$\mu\textrm{m}$ displacement more than cymbal actuator with uniformly thick bronze endcap. The displacement about 3mm in diameter at the center of the endcap was uniform and rapidly decreased away from 3mm in diameter at the center of the endcap.
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