통합 검색 | Korea Science

Cheng, Dong-kai;Ma, Hong-qiu;Cao, Dan;Ding, Fu-chang
- 한국분말야금학회:학술대회논문집
- /
- 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
- /
- pp.449-450
- /
- 2006
This paper described the preparation method for composing high-grade synthetic diamond by water atomizing using FeNi30 powder catalyst. The objective of this article is about powder making process using super high water atomizing in the atmosphere of inert gas, and then corroded the powder with a corrosion inhibitor. Finally, FeNi30 catalyst powder with lower oxygen content and good sphericity is produced. The experiment of making diamonds by using cubic press and the performance of the diamonds are also discussed.
PDF

노태환;김구현;최광보;김광윤
- 한국자기학회지
- /
- 제12권6호
- /
- pp.218-223
- /
- 2002
가슨 분무법으로 제조한 High-Flux형 $Ni_{x}Fe_{100-x}$(x=40~50, wt.%) 퍼멀로이 분말 및 압분 코아의 자기적 특성을 조사하였다. 포화자화는 45%Ni조성에서 최대 값을 보이며 이보다 보 함량이 낮아지면 인바 효과의 작용에 의해 급격하게 감소하였다. 압분 코아의 투자율은 Ni 농도가 낮아지면 현저히 증가하는 바 이는 자기변형의 감소에 기인하는 것으로 사료되었으며, 자심손실은 Ni=45%에서 가장 낮은 값을 나타내었다. Ni농도가 50%에서 45%로 낮아짐에 따라 자심손실이 감소하는 주원인은 전기 비저항의 증대에 따른 와전류 손실의 감소에 있는 것으로 생각되었다. Ni=45% 분말 합금으로 만든 압분 코아는 Ni=50%의 경우보다 더 우수한 투자율의 주파수 의존성, 큰 Q 값, 그리고 더 나은 직류 바이어스 특성을 나타내어 상용 High-Flux 코아(50%Ni-50%Fe)에 비해 더 좋은 압분 자심 재료가 될 수 있음을 확인하였다.
https://doi.org/10.4283/JKMS.2002.12.6.218 인용 PDF KSCI

임다미;박형근;;이병주;김형섭
- 한국분말재료학회지
- /
- 제25권3호
- /
- pp.208-212
- /
- 2018
In this paper, a new $Co_{10}Fe_{10}Mn_{35}Ni_{35}Zn_{10}$ high entropy alloy (HEA) is identified as a strong candidate for the single face-centered cubic (FCC) structure screened using the upgraded TCFE2000 thermodynamic CALPHAD database. The $Co_{10}Fe_{10}Mn_{35}Ni_{35}Zn_{10}$ HEA is fabricated using the mechanical (MA) procedure and pressure-less sintering method. The $Co_{10}Fe_{10}Mn_{35}Ni_{35}Zn_{10}$ HEA, which consists of elements with a large difference in melting point and atomic size, is successfully fabricated using powder metallurgy techniques. The MA behavior, microstructure, and mechanical properties of the $Co_{10}Fe_{10}Mn_{35}Ni_{35}Zn_{10}$ HEA are systematically studied to understand the MA behavior and develop advanced techniques for fabricating HEA products. After MA, a single FCC phase is found. After sintering at $900^{\circ}C$, the microstructure has an FCC single phase with an average grain size of $18{\mu}m$. Finally, the $Co_{10}Fe_{10}Mn_{35}Ni_{35}Zn_{10}$ HEA has a compressive yield strength of 302 MPa.
https://doi.org/10.4150/KPMI.2018.25.3.208 인용 PDF KSCI

Kim, Il-Ho;Kwun, S.I.
- 한국분말야금학회:학술대회논문집
- /
- 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
- /
- pp.962-963
- /
- 2006
The precipitation behaviors of ${\gamma}"(Ni_3Nb)$ in four Ni-base alloys were investigated. The four alloys were forged Ni20Cr20Fe5Nb alloy, mechanically alloyed Ni20Cr20Fe5Nb alloy, IN 718 alloy and ECAPed(equal channel angular pressing) IN 718 alloy. Aging treatment was employed at either $600^{\circ}C$ or $720^{\circ}C$ for 20 hrs. The TEM observation and hardness test were performed to identify the formation of ${\gamma}"$. The precipitation of ${\gamma}"$ was noticed after aging at $600^{\circ}C$ for 20 hrs in the mechanically alloyed Ni20Cr20Fe5Nb alloy and ECAPed IN 718 alloy, while it was observed after aging at $720^{\circ}C$ for 20 hrs in the forged Ni20Cr20Fe5Nb alloy and IN 718 alloy before ECAP. The lower aging temperature for ${\gamma}"$ precipitation in the mechanically alloyed Ni20Cr20Fe5Nb alloy and ECAPed IN 718 alloy than in the forged Ni20Cr20Fe5Nb alloy and IN 718 alloy before ECAP appeared to be due to the severe plastic deformation which occurred during mechanical alloying or ECAP.
PDF