• 제목/요약/키워드: Micro Powder

검색결과 475건 처리시간 0.03초

Powder Blasting을 이용한 도광판의 Micro-Pattern 가공기술 (Machining Technology of Micro-Patterns in LGP by Powder Blasting)

  • 박동삼;성은제;한진용;유우식
    • 소성∙가공
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    • 제15권9호
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    • pp.686-691
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    • 2006
  • Powder blasting technique was introduced to micromachine the micro patterns of circular and rectangular shape in LGP mould. The machinability of these patterns and matt treatment by powder blasting were verified. Then a prototype of LGP was injected by the developed LGP mould with micro patterns. Shape analysis of micro patterns and performance test of the injected LGP were carried out. The results showed printless LGP with micro patterns could be produced by just single injection using the mould with micro patterns, and powder blasting technique could be successfully applied to micrornachining of micro patterns and matt treatment of LGP mould.

LIGA 공정을 이용한 초소형 스퍼기어 금형 제작 및 하이브리드 분말 압출성형 (Fabrication of a Micro Die by LIGA Process and Hybrid Powder Extrusion Process of Micro-spur Gear)

  • 이경훈;황대원;김종현;장석상;김병민
    • 소성∙가공
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    • 제19권6호
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    • pp.352-356
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    • 2010
  • This paper was designed to fabricate the micro-spur gear by the LIGA and hybrid powder extrusion process. It is important to manufacture a micro-die with a high aspect ratio and determine appropriate extrusion conditions for a microforming. Ni has been used to fabricate micro-dies. LIGA process was capable to produce micro-extrusion dies with close tolerance, longer bearing length and adequate surface quality. Superplastic Al-78Zn powders have the great advantage in achieving deformation under low stresses and exhibiting good micro-formability with average strain rate raging from $10^{-3}$ to $10^{-2} s^{-1}$ and constant temperature ranging from 503 to 563K. Al-78Zn powders were compacted into a cylindrical shape ($\Phi3\times$h10mm) under compressive force of 10kN and, subsequently, the compacted powders were extruded by the hybrid powder extrusion process controlling of the temperature holing time for a improvement on formability of Al-22Zn powder. Micro-extrusion has succeeded in forming micro-gear shafts.

W-Cu의 마이크로 금속분말사출성형 (Micro Metal Powder Injection Molding in the W-Cu System)

  • 김순욱;양주환;박순섭;김영도;문인형
    • 한국분말재료학회지
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    • 제9권4호
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    • pp.267-272
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    • 2002
  • The production of micro components is one of the leading technologies in the fields of information and communiation, medical and biotechnology, and micro sensor and micro actuator system. Microfabrication (micromachining) techniques such as X-ray lithography, electroforming, micromolding and excimer laser ablation are used for the production of micro components out of silicon, polymer and a limited number of pure metals or binary alloys. However, since the first development of microfabrication technologies there have been demands for the cost-effective replication in large scale series as well as the extended range of available material. One such promising process is micro powder injection molding (PIM), which inherits the advantages of the conventional PIM technology, such as low production cost, shape complexity, applicability to many materials, applicability to many materials, and good tolerance. This paper reports on a fundamental investigation of the application of W-Cu powder to micro metal injection molding (MIM), especially in view of achieving a good filling and a safe removal of a micro mold conducted in the experiment. It is absolutely legitimate and meaningful, at the present state of the technique, to continue developing the micro MIM towards production processes for micro components.

나노 및 마이크로 알루미늄의 가수분해에 의한 알루미늄 수산화물의 형성 (Formation of Aluminum Hydroxides by Hydrolysis of Nano and Micro Al Powders)

  • 오영화;이근희;박중학;이창규;김흥회;김도향
    • 한국분말재료학회지
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    • 제12권3호
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    • pp.186-191
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    • 2005
  • A formation of aluminum hydroxide by hydrolysis of nano and micro aluminum powder has been studied. The nano aluminum powder of 80 to 100 nm in diameter was fabricated by a pulsed wire evaporation (PWE) method. The micro powder was commercial product with more than $10\;{\mu}m$ in diameter. The hydroxide type and morphology depending on size of the aluminum powder were examined by several analyses such as XRD, TEM, and BET. The hydrolysis procedure of micro aluminum powder was different from that of nano aluminum powder. The nano aluminum powder after immersing in the water was transformed rapidly to a nano fibrous boehmite, accompanying with a remarkable temperature increase, and then further transformed slowly to a stable bayerite. However, the micro powder was changed to the stable bayerite slowly and directly. The formation of fibrous aluminum hydroxide from nano aluminum powder might be due to the fine cracks which were formed by hydrogen gas pressure on the surface hydroxide layer during hydrolysis. The nano powder with large specific surface area and small size reacted more actively and faster than the micro powder, and transformed to meta-stable hydroxide in relatively short reaction time. Therefore, the formation of fibrous boehmite is special characteristic of hydrolysis of nano aluminum powder.

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

  • 오석훈;민병권;박성준;이상조
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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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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Micro Fabrication Process of Powder Compact with Semi-solid Mold

  • Tsumori, Fujio
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.258-259
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    • 2006
  • New powder compaction process, in which a Bingham semi-solid/fluid mold is utilized, is developed to fabricate micro parts. In the present process, a powder material is filled as slurry in a solid wax mold, dried and compressed. The wax is heated during compaction and becomes semi-solid state, which can acts as a pressurized medium for isostatic compaction. Since the compacted micro parts are very fragile, the mold's temperature is controlled to higher than its melting point during unloading, to avoid breakage of the compacts. To demonstrate effectiveness of this process, some micro compacts of alumina are shown as examples.

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Micro-porous Nickel Produced by Powder Metallurgy

  • Yamada, Y.;Li, Y.C.;Banno, T.;Xie, Z.K.;Wen, C.E.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.602-603
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    • 2006
  • Micro-porous nickel (Ni) with an open cell structure was fabricated by powder metallurgy. The pore size of the micro-porous Ni approximated $30{\mu}m$ and $150{\mu}m$. For comparison, porous Ni with a macro-porous structure were also prepared by both powder metallurgy (pore size $800{\mu}m$) and the traditional chemical vapour deposition method (pore size $1300{\mu}m$). The mechanical properties of the micro-and macro-porous Ni samples were evaluated using compressive tests. Results indicate that the micro-porous Ni samples exhibited significantly enhanced mechanical properties, compared to those of the macro-porous Ni samples.

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마이크로 PIM용 Fe 마이크로-나노 복합분말 피드스톡 제조시 혼합거동과 미세구조 변화 (Mixing Behavior and Microstructural Development During Fabrication of Fe Micro-nano-powder Feedstock for Micro-PIM)

  • 유우경;이재성;고세현;이원식
    • 대한금속재료학회지
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    • 제48권7호
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    • pp.630-638
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    • 2010
  • The present investigation has been performed on the mixing behavior and microstructural development during fabrication of Fe micro-nano powder feedstock for a micro-powder injection molding process. The mixing experiment using a screw type blender system was conducted to measure the variations of torque and temperature during mixing of Fe powder-binder feedstock with progressive powder loading for various nano-powder compositions up to 25%. It was found that the torque and the temperature required in the mixing of feedstock increased proportionally with increasing cumulative powder loading. Such an increment was larger in the feedstock containing higher content of nano-powder at the same powder loading condition. However, the maximum value was obtained at the nano-powder composition of not 25% but 10%. It was owing to the 'roller bearing effect' of agglomerate type nano-powder acting as lubricant during mixing, consequently leading to the rearrangement of micro-nano powder in the feedstock. It is concluded that the improvement of packing density by rearrangement of nano-powders into interstices of micro-powders is responsible for the maximum powder loading of about 71 vol.% in the nano-powder composition of 25%.

Powder Blasting 에 의한 유리의 미세 홈 가공시 노즐 주사횟수의 영향 (Effect of Nozzle Scanning in Micro Grooving of Glass by Powder Blasting)

  • 김광현;최종순;박동삼
    • 대한기계학회논문집A
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    • 제26권7호
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    • pp.1280-1287
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    • 2002
  • The old technique of sandblasting which has been used for decoration of glass surface has recently been developed into a powder blasting technique for brittle materials such as glass, silicon and ceramics, capable of producing micro structures larger than $100{\mu}$ m. This paper describes the performance of powder blasting technique in micro-line grooving of glass and the effect of the number of nozzle scanning on the depth and width of line groove. Experimental results showed that increasing the no. of nozzle scanning resulted in the increase of depth and width in grooves. Increase of width which may cause several problems in the precision machining results from wear of mask film. Therefore, well-controlled masking process is the most important factor for micro machining of glass with accuracy.

나노-마이크로 크기 하이브리드 구조 텅스텐 분말특성에 미치는 분말혼합 공정의 영향 (Effect of Powder Mixing Process on the Characteristics of Hybrid Structure Tungsten Powders with Nano-Micro Size)

  • 권나연;정영근;오승탁
    • 한국분말재료학회지
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    • 제24권5호
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    • pp.384-388
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    • 2017
  • The effect of the mixing method on the characteristics of hybrid-structure W powder with nano and micro sizes is investigated. Fine $WO_3$ powders with sizes of ${\sim}0.6{\mu}m$, prepared by ball milling for 10 h, are mixed with pure W powder with sizes of $12{\mu}m$ by various mixing process. In the case of simple mixing with ball-milled $WO_3$ and micro sized W powders, $WO_3$ particles are locally present in the form of agglomerates in the surface of large W powders, but in the case of ball milling, a relatively uniform distribution of $WO_3$ particles is exhibited. The microstructural observation reveals that the ball milled $WO_3$ powder, heat-treated at $750^{\circ}C$ for 1 h in a hydrogen atmosphere, is fine W particles of ~200 nm or less. The powder mixture prepared by simple mixing and hydrogen reduction exhibits the formation of coarse W particles with agglomeration of the micro sized W powder on the surface. Conversely, in the powder mixture fabricated by ball milling and hydrogen reduction, a uniform distribution of fine W particles forming nano-micro sized hybrid structure is observed.