• Title/Summary/Keyword: powder fabrication

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Fabrication of Al 6061 Foamable Precursor by Powder Metallurgical and Induction Heating Method (P/M법과 유도가열 공정을 이용한 발포용 6061 Al 합금 프리커서 제조)

  • 윤성원;강충길
    • Transactions of Materials Processing
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    • v.12 no.5
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    • pp.457-464
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    • 2003

  • In the powder compact melting technique, proper precursor fabrication is very important because density distribution after foaming and foamability are determined during precursor fabrication process. The fabrication of the precursor has to be performed very carefully because any residual porosity or other defects will lead to poor results in further processing. In order to evaluate the effect of the compaction parameters on the kinetics of the foaming process, a series of experiments were performed. In this study, aluminium foams with a closed cell structure were fabricated by using both the powder compact method and the induction heating process. A proper induction coil was designed to obtain a uniform temperature distribution over the entire cross sectional area of precursor. To establish the foamable precursor fabrication conditions, effects of process parameters such as the titanium hydride content (0.3∼1.5 wt.%), pressing pressure of the foamable precursor (50∼150kN) on the pore morphology were investigated.

  • https://doi.org/10.5228/KSPP.2003.12.5.457 인용 PDF KSCI

Fabrication and Evaluation of Carbon Nanotube Reinforced Al Matrix Composite by a Powder-in-sheath Rolling Method (분말시스압연법에 의한 CNT 강화 Al기 복합재료의 제조 및 평가)

  • Lee, Seong-Hee;Hong, Dongmin
    • Journal of Powder Materials
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    • v.21 no.1
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    • pp.50-54
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    • 2014

  • A powder-in-sheath rolling method was applied to a fabrication of a carbon nano tube (CNT) reinforced aluminum composite. A STS304 tube with an outer diameter of 34 mm and a wall thickness of 2 mm was used as a sheath material. A mixture of pure aluminum powders and CNTs with the volume contents of 1, 3, 5 vol was filled in the tube by tap filling and then processed to 73.5% height reduction by a rolling mill. The relative density of the CNT/Al composite fabricated by the powder-in-sheath rolling decreased slightly with increasing of CNTs content, but exhibited high value more than 98. The grain size of the aluminum matrix was largely decreased with addition of CNTs; it decreased from $24{\mu}m$ to $0.9{\mu}m$ by the addition of only 1 volCNT. The average hardness of the composites increased by approximately 3 times with the addition of CNTs, comparing to that of unreinforced pure aluminum. It is concluded that the powder-in-sheath rolling method is an effective process for fabrication of CNT reinforced Al matrix composites.

  • https://doi.org/10.4150/KPMI.2014.21.1.50 인용 PDF KSCI

Fabrication of Micro Structure Using Electro Discharge Deposition (Electro Discharge Deposition (EDD)을 이용한 미세 구조물 제작)

  • 오석훈;민병권;박성준;이상조
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.1865-1868
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    • 2003

  • This paper provides a new method for hybrid machining, particularly suited to micro fabrication applications such as micro point, micro line, micro structure, micro partition and so on. Developed micro fabrication process by electrical discharge machining (EDM) and electrical discharge deposition (EDD) with metal powder (Ti, Fe) has been studied to build TiC or FeC structure. Titanium powder or iron powder is supplied from working fluid (kerosene or de-ionized water with powder) and adheres on a workpiece by the heat and electric power caused by the electrical discharge. The use of a tool electrode is expected to keep powder concentration high in the gap between a workpiece and a tool electrode and to accrete powder material on the workpiece. The deposition is tried under various electrical conditions (workpiece. tool electrode, working fluid, discharge current, voltage and powder etc.). On the other hand. using electrical discharge machining (EDM) with the same tool electrode, it can be used as a removal process (cutting) by electro erosion at the same time. Therefore. this new method can do a hybrid machining to build up and down a structure with the workpiece.

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