• 제목/요약/키워드: Intermetallics.

검색결과 115건 처리시간 0.021초

고주파 유도가열을 통한 알루미늄 기판재위 Ni-Al계 금속간화합물의 연소합성코팅에 관한 연구 (A Study for Ni-Al based Intermetallics Coating onto Aluminum Substrate by Induction Heating)

  • 이한영
    • Tribology and Lubricants
    • /
    • 제28권2호
    • /
    • pp.56-61
    • /
    • 2012
  • In order to investigate the possibility of Ni-Al based intermetallics coating onto aluminum substrate, the coating process for induction heating has been evaluated by microscopically analyzing the intermetallic layers coated at temperatures lower than the melting temperature of aluminum. The coating layers were divided into two parts with different microstructure along the depth. Hard $NiAl_3$ layer was found at lower parts of the coatings near the interface with aluminum substrate. This layer was formed by the diffusion of aluminum atoms from the substrate into the coating layer across the interface during the induction heating. Meanwhile, at the upper parts of the coating near the surface, a large amount of un-reacted Ni was still remained and surrounded by several Ni-Al based intermetallic compounds, such as $Ni_3Al$, NiAl and $Ni_2Al_3$ formed by the lattice diffusion.

Synthesis of Intermetallics and Nanocomposites by High-Energy Milling

  • Bernd F. Kieback;H. Kubsch;Alexander Bohm;M. Zumdick;Thomas Weissgaerber
    • 한국분말재료학회지
    • /
    • 제9권6호
    • /
    • pp.416-421
    • /
    • 2002
  • Elemental powders are used in high energy milling processes for the synthesis of new compounds. The low temperature solid state reactions during milling in inert gas atmosphere may result in intermetallic phases, carbides, nitrides or silicides with a nanocrystalline structure. To obtain dense materials from the powders a pressure assisted densification is necessary. On the other side the defect-rich microstructure can be used for activated sintering of elemental powder mixtures to obtain dense bodies by pressureless sintering. Results are discussed for nanocrystalline cermet systems and for the sintering of aluminides and silicides.

Effect of Cu and Mg on Forging Property and Mechanical Behavior of Powder Forged Al-Si-Fe Based Alloy

  • Lee, Dong-Suk;Jung, Taek-Kyun;Kim, Mok-Soon;Kim, Won-Yong
    • 한국분말야금학회:학술대회논문집
    • /
    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
    • /
    • pp.1000-1001
    • /
    • 2006
  • Two atomized alloy powders were pre-compacted by cold and subsequently hot forged at temperatures ranging from 653K to 845K. The addition of Cu and Mg causes a decrease in the eutectic reaction temperature of Al-10Si-5Fe-1Zr alloy from 841K to 786K and results in a decrease of flow stress at the given forging temperature. TEM observation revealed that in addition to Al-Fe based intermetallics, $Al_2Cu$ and $Al_2CuMg$ intermetallics appeared. The volume fraction of intermetallic dispersoids increased by the addition of Cu and Mg. Compressive strength of the present alloys was closely related to the volume fraction of intermetallic dispersoids.

  • PDF

어닐링처리한 Ni-50at%Al 압분체의 연소합성 거동 (Reaction Synthesis of Annealed Ni-50at%Al Powder Compact)

  • 조용재;이한영
    • 대한금속재료학회지
    • /
    • 제49권10호
    • /
    • pp.790-796
    • /
    • 2011
  • To reduce the heat released during intermetallic reaction, Ni-50at%Al powder compact has been previously annealed at several conditions before the reaction. The effects of the pre-annealing conditions on the reaction synthesis process have been investigated. Experimental results show that the heat released during the reaction synthesis decreased proportionally with increase of the pre-annealing temperature and duration time. The reaction duration period was significantly increased when the intermetallics were formed in the powder compact during the pre-annealing. This was attributed to the fact that the reaction occurred by solid-state diffusion between the un-reacted elemental atoms and that the $NiAl_3$ phase formed predominantly during pre-annealing.