• 제목/요약/키워드: Aluminum Scrap

검색결과 34건 처리시간 0.024초

스크랩 장입 비율에 따른 다이캐스팅용 알루미늄 합금의 부식 특성 (Corrosion Characteristics of Aluminum Die Casting Alloys with Different Scrap Charge Rate)

  • 김준호;이승효
    • 한국표면공학회지
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    • 제53권6호
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    • pp.322-329
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    • 2020
  • The utilization of aluminum scrap is a subject of great importance in terms of reducing energy consumption and environmental protection. However, aluminum scrap contains impurities, which can degrade the properties of aluminum alloy, especially corrosion resistance. This study examines the effect of scrap charge rate of aluminum alloys about microstructures and corrosion characteristics. According to the metallographic examinations, Mg2Si tended to become coarser and its uniformity was decreased by increasing aluminum scrap charge rate. The immersion test exhibited corrosion progressed through the eutectic areas due to micro-galvanic interactions. Electrochemical measurements revealed that excess aluminum scrap could reduce the intergranular corrosion resistance of aluminum alloys. Results showed that the scrap charge rate is important factor in the design of corrosion resistance of aluminum die casting alloys.

알루미늄칩과 타공판을 이용한 방음벽 충진재의 흡음특성 (Absorption Characteristics of Sound Proof Wall by Scrap Aluminum and Perforated Plate)

  • 이영중;김대건;박경화;김영도
    • 한국재료학회지
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    • 제19권7호
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    • pp.382-385
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    • 2009
  • Efforts to reduce noise in industrial application fields, such as automobiles, aircrafts, and plants have been gaining considerable attention while a sound proof wall to protect people from the noise has been intensively investigated by many researchers. In this study, our research group suggested creating a new sound proof wall composed of scrap aluminum chips and perforated plates in a commercial polyester sound proof wall, which was then successfully fabricated. This wall's sound absorption characteristics were measured by an impedance tube method. The sound absorption property was evaluated by measuring the Noise Reduction Coefficient (NRC) to the standard, ASTM C 423-90a. The noise reduction coefficient of the sound proof wall composed of 3.5 vol.% and 7.5 vol.% of scrap aluminum chips relatively increased to 5% and 8% compared to the commercial polyester sound proof wall. The scrap aluminum perforated plate also relatively increased to 13% compared to the commercial polyester sound proof wall.

알루미늄의 리사이클링 기술 (Recycling Technologies of Aluminum)

  • 손호상
    • 자원리싸이클링
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    • 제28권2호
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    • pp.3-13
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    • 2019
  • 알루미늄은 지각 구성 원소 중 실리콘에 이어 두 번째로 풍부한 금속원소이다. 알루미늄은 가볍고, 전기전도도가 우수하고, 내식성이 우수하지만 산소와의 친화력이 강한 특성을 가지고 있다. 그러나 알루미늄의 1차 지금을 제조하기 위해서는 다량의 에너지를 소비한다. 한편 알루미늄 스크랩을 리사이클링하면 1차 지금 생산과 비교하여 에너지 및 환경부하를 저감할 수 있다. 그러나 알루미늄 스크랩 중의 불순물 제거가 곤란하여 재생되는 양은 한정되어 있다. 본 논문에서는 알루미나의 제조부터 스크랩 처리 및 용융까지의 알루미늄 생산 및 리사이클링 공정에 대하여 고찰하였다.

AC4A 알루미늄 합금의 인장 및 응고균열 특성에 미치는 스크랩 첨가 비율의 영향 (Effect of Scrap Addition Ratio on Tensile and Solidification Cracking Properties of AC4A Aluminum Casting Alloy)

  • 오승환;김헌주
    • 한국주조공학회지
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    • 제40권3호
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    • pp.85-96
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    • 2020
  • The effect of an aluminum scrap addition ratio on the tensile and solidification cracking properties of the AC4A aluminum alloy in the as-cast state and heat-treated state were investigated in this study. Generally, the expected problem of using scrap in aluminum casting is an increase of hydrogen and Fe element inside the aluminum melt. Another issue is an oxide film which has a weak interface with the molten aluminum and acts as potent nucleation sites for internal porosity and crack initiation. Solidification cracking is one of the critical defects that must be resolved to produce high quality castings. A conventional evaluation method for solidification cracking is a relative and qualitative analysis method which does not provide quantitative data on the thermal stress in the solidification process. Therefore, a newly designed solidification cracking test apparatus was used in this study, and the device can provide quantitative data. As a result, after conducting experiments with different scrap addition ratios (0%, 20%, 35%, 50%), the tensile strengths and elongations in the as-cast state were 214, 187.7, 182.1 and 170.4MPa and 4.6%, 3.4%, 3.1% and 2.3%, respectively. In the case of the T6 heat-treated state, the tensile strengths and elongations were 314.9, 294.6, 293.1 and 271.1MPa and 5.4%, 4.6%, 3.8% and 3.1%, respectively. The strength of the solidification cracking was 3.1, 2.4, 2.2and 1.6MPa as the scrap addition ratio increases.

재활용 스크랩 함유 Al-Si-Cu계 합금의 주조특성에 미치는 결정립 미세화제와 공정 Si 개량화제의 영향 (Effect of Grain Refiner and Eutectic Si Modifier on Casting Properties of Al-Si-Cu Alloy System Containing Recycled Scrap)

  • 성동현;김헌주
    • 한국주조공학회지
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    • 제38권6호
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    • pp.121-131
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    • 2018
  • The effect of additives on the castability of the AC2BS aluminum alloy, which contains 35% recycled scrap, was investigated. For the wide utilization of the recycled scrap AC2BS aluminum alloy, the research results were compared to those with the AC2B virgin alloy, which is typical Al-Si-Cu alloy system. It was confirmed that the addition of Al-5%Ti-1%B increased the ${\alpha}$-Al nucleation temperature during solidification and decreased the grain size through cooling curve and microstructural observations of the recycled alloy. It was also found that an addition of Al-10%Sr decreased the eutectic Si growth temperature during the solidification process and modified the shape of the eutectic Si of the recycled alloy. The characteristics of fluidity, shrinkage and solidification crack strength were evaluated. For the AC2BS aluminum alloy containing 35% recycled scrap, both ${\alpha}$-Al grain refinement due to Ti-B and eutectic Si modifications due to Sr contributed to the improvement of the fluidity. The macro- shrinkage ratio increased with additions of both Al-10%Sr and Al-5%Ti-1%B and the micro-shrinkage ratio increased with the addition of Al-10%Sr but decreased with the addition of Al-5%Ti-1%B. The casting characteristics of TiB and Sr-treated AC2BS aluminum alloy containing 35% recycled scrap are similar to those of AC2B virgin alloy. The improvement of the solidification crack strength of the AC2BS aluminum alloy was possible by the reduction of the grain boundary the stress concentration through the enhancement by both ${\bullet}{\cdot}$-Al refinement and eutectic Si modification. More extensive use of the AC2BS aluminum alloy containing 35% recycled scrap can be expected in the future.

알루미늄 캔 스크랩의 용탕처리 시 알루미늄 합금 회수에 미치는 플럭스의 영향 (Effect of Flux on Recovery of Aluminum During Molten Metal Treatment of Aluminum Can Scrap)

  • 한철웅;안병두;김대근;이만승;김용환
    • 자원리싸이클링
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    • 제29권1호
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    • pp.70-80
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    • 2020
  • 본 연구에서는 유도로를 사용하여 알루미늄 캔 스크랩의 재활용 효율을 플럭스 종류와 혼합 비율의 영향에 대해 조사하였다. 알루미늄 캔 제조 공정에서 발생한 알루미늄 캔 스크랩의 표면 코팅층 약 500 ℃에서 30 분간 열처리를 통해 제거가 가능하였다. 용해 공정 온도는 알루미늄 합금 용해 온도보다 높은 온도로 설정하였고, 플럭스 종류와 혼합 비율에 따른 용탕처리를 진행하였다. 그 결과, 750 ℃에서 3 wt.%의 플럭스(Salt flux와 MgCl2 혼합비율 70:30)의 조건에서 알루미늄을 최적으로 회수 할 수 있었다. 회수된 Al합금은 인장강도 249 MPa과 연신율 14 %로써 Al5083 소재와 거의 동일한 기계적 특성을 나타냄을 알 수 있었다.

알루미늄 스크랩의 재활용을 위한 전자기장 펌프의 열 유동 해석에 의한 장비 설계 (The Equipment Design by the Fluid and Thermal Analysis of the Electromagnetic Pump for Recycling of Aluminum Scrap)

  • 최우식;강충길
    • 한국정밀공학회지
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    • 제23권12호
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    • pp.64-71
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    • 2006
  • In this study, to design aluminum scrap recycling equipment, fluid flow and thermal analysis considering electromagnetic phenomenon were carried out by using ANSYS program. The magnetic flux generated by electromagnetic pump has influence on fluid velocity of Al liquid metal with molten metal motion and thermal generation. To investigate the effect of the number of phase on fluid flow and thermal generation, electromagnetic force and magnetic flux were obtained by computer simulation. In addition, the results obtained by fluid flow and thermal analysis, recycling equipment of aluminum scrap with the cooling technology of electromagnetic coil, the most suitable phase and current were proposed.

공업용 순알루미늄의 전기전도도에 미치는 스크랩비율 및 GBF처리조건의 영향 (Effects of GBF Treatment Conditions and Scrap Ratio on the Electric Conductivity of Commercial Pure Aluminum)

  • 황남규;김영찬;최세원;강창석;홍성길
    • 한국주조공학회지
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    • 제31권3호
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    • pp.130-136
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    • 2011
  • Effects of GBF (gas bubbling filtration) treatment conditions and scrap ratio on the electric conductivity of a commercial pure aluminum for diecasting were investigated using by specific gravity and electrical conductivity measurement system, hydrogen gas analyzer, XRD, and EDS. Electrical conductivities of specimen mixed Al scrap ratio until 60% from 0% were decreased with increasing the precipitates amount and size of AlFeSi ternary intermetallic compound on the grain boundary as well as amount of porosity in the grain. On the other hand, electrical conductivities was reincreased gradually in spite of scrap ratio increase from 80% to 100%. Size of AlFeSi compound formed on the grain boundary were coarsened with the increament of scrap ratios untill 80% and GBF treatment time simultaneously.

전자기력을 이용한 알루미늄 스크랩 중의 Fe 제거에 관한 연구;Part 2. Al-Si-Cu계 합금 스크랩에서 전자기력에 따른 Fe계 금속간화합물의 이동양상 (A Study on the Elimination of Fe Elements in Aluminum Alloy by Electromagnetic Force;Part 2. The Movement of Fe-Contained Intermetallics with Electromagnetic Force in Al-Si-Cu Scrap)

  • 김정호;노정훈;박준표;윤의박
    • 한국주조공학회지
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    • 제18권3호
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    • pp.240-245
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    • 1998
  • In the view point of the environmental conservation and the energy reduction, the recycling of metal scrap is coming as one of the global subjects in the world. In this study, the movement of intermetallics with electromagnetic force in a melt of a scrap of Al-Si-Cu alloy (JIS ADC12), which was widely used in diecasting process, was investigated in order to eliminate the Fe element, which was usually accumulated in a scrap. In this study, we applied electromagnetic method to eliminate Fe element in ADC12 aluminum alloy scrap which contains 1.64wt.% Fe and the effects of electromagnetic force on the particle movement was visualized and confirmed by water modeling and experiment. As a result, the Fe intermetallic compounds are moved to the direction opposite to that of the electromagnetic force as the force applies, thus eliminated from the bulk metal. Therefore, the content of Fe in matrix decreased from 1.64wt.% to 0.45wt.%.

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재활용 AC4A 알루미늄 합금의 인장특성에 미치는 (Ti-B), Sr 첨가제의 영향 (Effect of Sr and (Ti-B) Additives on Tensile Properties of AC4A Recycled Aluminum Casting Alloys)

  • 오승환;김헌주
    • 한국주조공학회지
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    • 제38권5호
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    • pp.87-94
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    • 2018
  • The effects of Sr and (Ti-B) additives on the tensile properties of AC4A recycled (35% scrap content) aluminum alloys were investigated. An acicular morphology of the eutectic Si phase of as-cast specimens was converted to a fibrous morphology upon the addition of Sr. Moreover, morphology of the Sr modified eutectic Si phase became finer due to a T6 heat treatment. The grain size of the ${\alpha}$-solid solution was decreased by the addition of (Ti-B) additives. Depending on the treatment conditions of the as-cast specimens, i.e., no addition, a Sr addition and a (Ti-B)+Sr addition, the tensile strength levels of the as-cast specimens were 182, 192, and 204MPa, respectively. The corresponding strengths of T6 heat-treated specimens were 293, 308, and 318MPa. Elongations of the as-cast specimens were 2.2, 3.1, and 5.6%, and the corresponding elongations of the T6 heat-treated specimens were 4.6, 6.1, and 7.6%. The percentage of the reduced section area in the tensile specimens was also increased by the Sr and (Ti-B) additives. Sr and (Ti-B) additives changed the microstructure and the distribution of defects in the castings, resulting in an improvement of the tensile properties of AC4A aluminum alloys. According to our test results, recycled (35% scrap content) AC4A aluminum alloy met all of the KS requirements of the tensile strength and elongation values of AC4A aluminum alloy except for the elongation value of the one specimen condition, in this case the as-cast no-addition condition.