• 제목/요약/키워드: high silicon aluminum alloy

검색결과 24건 처리시간 0.024초

고규소 알루미늄 합금의 표면에 PEO 공정에 의하여 형성된 산화물 층의 부식 거동 (Corrosion behavior of oxide layer formed on surface of high silicon aluminum alloy by PEO process)

  • 박덕용
    • 한국표면공학회지
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    • 제56권4호
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    • pp.250-258
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    • 2023
  • Ceramic oxide layer was formed on the surface of high silicon aluminum alloy by using PEO (plasma electrolytic oxidation) process. The microstructure of the oxide layer was analyzed using scanning electron microscopy (SEM) and x-ray diffraction patterns (XRD). The high silicon aluminum alloy prior to PEO process consists of Al, Si and Al2Cu phases in XRD analysis, whereas Al2Cu phase selectively disappeared after PEO treatment. Considerable decrease of relative intensity in most of peaks in XRD results of the high silicon aluminum alloy treated by PEO process was observed. It may be attributed to the formation of amorphous phases after PEO treatment. The corrosion behavior of the high silicon aluminum alloy treated by PEO process was investigated using electrochemical impedance spectroscopy (EIS) and other electrochemical techniques (i.e., open circuit potential and polarization curve). Electroanalytical studies indicated that the high silicon aluminum alloy treated by PEO process shows greater corrosion resistance than that untreated by PEO process.

3D 프린팅으로 제조한 알루미늄 합금의 크로메이트 코팅 (Chromate Conversion Coating on 3D Printed Aluminum Alloys)

  • 신홍식;김효태;김기승;최혜윤
    • 한국기계가공학회지
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    • 제21권2호
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    • pp.109-115
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    • 2022
  • The demand for metal 3D printing technology is increasing in various industries. The materials commonly used for metal 3D printing include aluminum alloys, titanium alloys, and stainless steel. In particular, for applications in the aviation and defense industry, aluminum alloy 3D printing parts are being produced. To improve the corrosion resistance in the 3D printed aluminum alloy outputs, a post-treatment process, such as chromate coating, should be applied. However, powdered materials, such as AlSi7Mg and AlSi10Mg, used for 3D printing, have a high silicon content; therefore, a suitable pretreatment is required for chromate coating. In the desmut step of the pretreatment process, the chromate coating can be formed only when a smut composed of silicon compounds or oxides is effectively removed. In this study, suitable desmut solutions for 3D printed AlSi7Mg and AlSi10Mg materials with high silicon contents were presented, and the chromate coating properties were studied accordingly. The smut removal effect was confirmed using an aqueous desmut solution composed of sulfuric, nitric, and hydrofluoric acids. Thus, a chromate coating was successfully formed. The surfaces of the aluminum alloys after desmut and chromate coating were analyzed using SEM and EDS.

용매정제법과 원심분리법으로 추출한 Si의 순도에 미치는 장입 원재료 순도의 영향 (The Effect of the Purity of Raw Materials on the Purity of Silicon Extracted by Solvent Refining and Centrifugation)

  • 조주영;서금희;강복현;김기영
    • 대한금속재료학회지
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    • 제50권12호
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    • pp.907-911
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    • 2012
  • High purity silicon can be obtained from Al-Si alloys by a combination of solvent refining and centrifugation. Silicon purification by crystallization of silicon from an Al-Si alloy melt was carried out using 2N and 4N purity aluminum and 2N purity silicon as raw materials. The effect of the purity of raw materials on the final silicon ingot purity by centrifugation was investigated for an Al-50 wt% Si alloy. Alloys were melted using an electrical resistance furnace, and then poured into a centrifuging apparatus. A silicon lump like foam was obtained after centrifugation and was leached by an acid in order to get pure silicon flakes. Then silicon flakes were melted to make a silicon ingot using an induction furnace. The purities of the silicon flakes and silicon ingot were enhanced significantly compared to those of the raw materials of silicon and aluminum. The silicon ingot made of 4N aluminum and 2N silicon showed the lowest impurities.

Al-Zn-Fe-Si 합금의 물성 및 주조특성 (Properties and Casting Characteristics of Al-Zn-Fe-Si Alloys)

  • 윤호섭;김정민;박준식;김기태
    • 한국주조공학회지
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    • 제33권1호
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    • pp.8-12
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    • 2013
  • Although aluminum-silicon based commercial casting alloys have been used in applications that demand high electrical or thermal conductivity, new aluminum casting alloys that possess higher conductivities are currently required for advanced applications. Therefore, there is much research into the development of new high conductivity aluminum casting alloys that contain lower amounts of or no silicon. In this research, the properties and casting characteristics of Al-Zn-Fe-Si alloys with various Fe and Si contents were investigated. Two types of AlFeSi phases were formed depending on the Fe and Si contents. As the silicon content increased, the tensile strength of the Al-Zn-Fe-Si alloy increased slightly, while the electrical conductivity decreased slightly. It was also observed that both the fluidity and hot cracking susceptibility of the investigated alloys were closely related to the formation of the AlFeSi phases.

EFFECT OF MICROSTRUCTURE ON MECHANICAL PROPERTIES IN FRICTION STIR WELDED CAST A356 ALUMINUM ALLOY

  • Sato, Yutaka S.;Kaneko, Takayasu;Urata, Mitsunori;Kokawa, Hiroyuki
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.493-498
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    • 2002
  • Friction stir welding (FSW) is a relatively new solid-state joining process which can homogenize the heterogeneous microstructure by intensely plastic deformation arising from the rotation of the welding tool. The present study applied the FSW to an A356 aluminum (AI) alloy with the as-cast heterogeneous microstructure in the T6 temper condition, and examined an effect of microstructure on mechanical properties in the weld. The base material consisted of Al matrix with a high density of strengthening precipitates, large eutectic silicon and a lot of porosities. The FSW led to fragment of the eutectic silicon, extinction of the porosities and dissolution of the strengthening precipitates in the Al alloy. The dissolution of strengthening precipitates reduced the hardness of the weld around the weld center and the transverse ultimate tensile strength of the weld. Longitudinal tensile specimen containing only the stir zone showed the roughly same strength as the base material and a much larger elongation. Moreover, Charpy impact tests indicated that the stir zone had remarkably the higher absorbed energy than the base material. The higher mechanical properties of the stir zone were attributed to a homogenization of the as-cast heterogeneous microstructure by FSW.

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고전도성 부품용 Al-Fe-Zn-Cu합금의 물성 및 주조성 (Properties and Casting Capabilities of Al-Fe-Zn-Cu Alloys for High Conductivity Parts)

  • 윤호섭;김정민;박준식;김기태;고세현
    • 한국주조공학회지
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    • 제33권6호
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    • pp.242-247
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    • 2013
  • The most widely utilized commercial, aluminum-casting alloys are based on an aluminum-silicon system due to its excellent casting, and good mechanical, properties. Unfortunately, these Al-Si based alloys are inherently poor energy conductors; compared to pure aluminum, because of their high silicon content. This means that they are not suitable for applications demanding high eletrical or thermal conductivity. Therefore, efforts are currently being made to develop new, highly-conductive aluminum-casting alloys containing no silicon. In this research, a number of properties; including potential for castability, were investigated for a number of Al-Fe-Zn-Cu alloys with varying Cu content. As the copper content was increased, the tensile strength of Al-Fe-Zn-Cu alloy tended to increase gradually, while the electrical conductivity was slightly reduced. Fluidity was found to be lower in high-Cu alloys, and susceptibility to hot-cracking was generally high in all the alloys investigated.

전자기 진동을 이용한 Al-Si 합금의 조직 제어에 관한 연구 (A Study on the Structural Controlling of Al-Si Alloy by Using Electromagnetic Vibration)

  • 최정평;김기배;남태운;윤의박
    • 한국주조공학회지
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    • 제26권5호
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    • pp.205-210
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    • 2006
  • 여러 전자기 재료 프로세싱 연구 중에서 연구 되어지지 않았던 Al-Si 합금의 조직제어를 직류 자기장과 교류 전류장을 사용하여 시도 하였다. 본 연구의 목적은 Al-Si 합금에서의 새로운 거시, 미시 조직제어를 하기 위해 사용된 전자기 진동의 영향을 조사하는 것이다. 전자기 진동이 초정 알루미늄의 형상 변화를 위해 낮은 진동수 (>60Hz)로 주어질 경우, 수지상의 형상이 구상화 형상으로 변해갔다. 전자기 진동이 공정 실리콘 형상 변화를 위해 주어졌을 경우, 높은 진동수 (>500Hz)에서 조대한 판상 조직이던 실리콘이 미세한 섬유상 조직으로 변화하고, 기계적 성질도 우수해졌다.

저온 알루미늄 브레이징용 Al-Cu-Si-Sn 합금 설계 및 분말 제조 (Alloy Design and Powder Manufacturing of Al-Cu-Si alloy for Low-Temperature Aluminum Brazing)

  • 김희연;박천웅;이원희;김영도
    • 한국분말재료학회지
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    • 제30권4호
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    • pp.339-345
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    • 2023
  • This study investigates the melting point and brazing properties of the aluminum (Al)-copper (Cu)-silicon (Si)-tin (Sn) alloy fabricated for low-temperature brazing based on the alloy design. Specifically, the Al-20Cu-10Si-Sn alloy is examined and confirmed to possess a melting point of approximately 520℃. Analysis of the melting point of the alloy based on composition reveals that the melting temperature tends to decrease with increasing Cu and Si content, along with a corresponding decrease as the Sn content rises. This study verifies that the Al-20Cu-10Si-5Sn alloy exhibits high liquidity and favorable mechanical properties for brazing through the joint gap filling test and Vickers hardness measurements. Additionally, a powder fabricated using the Al-20Cu-10Si-5Sn alloy demonstrates a melting point of around 515℃ following melting point analysis. Consequently, it is deemed highly suitable for use as a low-temperature Al brazing material.

단결정 다이아몬드 절삭에 의한 과공정 Al-Si합금의 경제성에 관한 연구 (A study on the economics of hypereutectic Al-Si alloy cutting with single crystal diamond tool)

  • 이은상;김정두
    • 대한기계학회논문집
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    • 제18권5호
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    • pp.1096-1105
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    • 1994
  • A hypereutectic Aluminum-Silicon Alloy is widely used in the parts of automobile because of high-resistance and good strength. In this study, the cutting of hypereutectic A1-Si alloy for economical production was investigated by simulation. Tool life and the extraction rate of Si particles is inversely proportional to the depth of cut. When decreasing the depth of cut, the reduction of single crystal diamond tool cost and tool change time is achieved.