서지주요정보
W-Ni-Fe 중합금에서 불순물의 영향과 기계적 성질의 향상에 관한 연구 = Effect of impurities and improvement of mechanical properties in W-Ni-Fe heavy alloy
서명 / 저자 W-Ni-Fe 중합금에서 불순물의 영향과 기계적 성질의 향상에 관한 연구 = Effect of impurities and improvement of mechanical properties in W-Ni-Fe heavy alloy / 홍성현.
저자명 홍성현 ; Hong, Seong-Hyun
발행사항 [대전 : 한국과학기술원, 1991
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소장정보

등록번호

8001519

소장위치/청구기호

학술문화관(문화관) 보존서고

DMS 9116

휴대폰 전송

도서상태

이용가능

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초록정보

The embrittlement by phosphorus and sulfur and its prevention by lanthanum and calcium have been investigated in 93W-4.9Ni-2.1Fe heavy alloy. Powder compacts have been sintered at 1475℃ for 60 or 100 min in hydrogen, heat treated at 1150℃ for one hour in nitrogen, and then water quenched. Toughness decreases drastically with phosphorous or sulfur addition of a few tens ppm, in contrast to much less sensitive decrease of tensile properties. Auger electron spectroscopy and scanning electron micrography have revealed that the phosphorous and sulfur segregate at W/matrix and W/W interfaces and cause brittle fracture. Addition of lanthanum to specimens containing 150 ppm, phosphorous suppresses the segregation of phosphorous at the interfaces by forming La-O-P base compounds and thus prevents the brittle failure. The impact energy of un-doped heavy alloys which did not show any P embrittlement after water quenching decreases drastically with decreasing the cooling rate from the heat-treatment temperatures or aging at 600℃ for 1h. The serious reduction of impact energy can be avoided by adding La or ca which forms P and O containing compounds. Calcium and lanthanum is also observed to suppress the sulfur segregation in S-doped alloys by forming S containing Ca or La compounds, and therefore prevent the sulfur embrittlement. The addition of lanthanum and calciun have ensured good mechinical properties of heavy alloys.

서지기타정보

서지기타정보
청구기호 {DMS 9116
형태사항 [iii], 124 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Seong-Hyun Hong
지도교수의 한글표기 : 강석중
지도교수의 영문표기 : Suk-Joong L. Kang
학위논문 학위논문(박사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 116-119
주제 Contamination (Technology)
Scanning electron microscopes
Tungstens alloys
취성 --과학기술용어시소러스
불순물 (화학) --과학기술용어시소러스
텅스텐 합금 --과학기술용어시소러스
Metals --Embrifflement
중합금
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