• Title, Summary, Keyword: 알루미늄 합금 주조

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Technology Trend of Powder-Metallurgical Aluminum Parts (알루미늄 분말야금부품의 기술동향)

  • Lee, Jae-Wook;Yang, Sang-Sun;Kim, Yong-Jin
    • Journal of Korean Powder Metallurgy Institute
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    • v.14 no.6
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    • pp.339-347
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    • 2007
  • 알루미늄 분말야금부품은 철계 분말부품에 비해 가볍고 알루미늄 주조부품에 비해 우수한 기계적 물성을 갖는다. 단, 상대적으로 비싼 가격이 이 부품의 응용을 제약하는 장벽이었으나 최근의 환경과 에너지 문제에 대한 세계적인 관심은 이를 극복할 수 있는 계기를 제공하고 있다. 선진국은 이미 일본을 중심으로 1990년대부터 알루미늄 분말부품에 대한 기술개발을 진행하였고 현재는 다양한 상용 부품을 판매하고 있으며 조만간 그 판매량이 크게 증가할 것으로 예상된다. 이에 이 글에서는 국내 관련 연구자들의 이해를 돕고자 알루미늄 분말야금부품의 국내외 기술개발 동향, 특허 동향, 원재료 동향 등을 분석하여 소개한다.

Evolution of Metastable $L1_2-Al_3(Nb_xZr_{1-x})$ Phases in Rapidly Quenched Al-Nb-Zr Alloys

  • Park, Min-Woo
    • Journal of Korea Foundry Society
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    • v.27 no.6
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    • pp.250-254
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    • 2007
  • 3원계 Al-Nb-Zr의 용응 합금을 스프렛 ?봬?(splat-quenching) 방법을 이용하여 급속냉각응고 한 후, 응고된 시편을 698K에서 200시간까지 열처리하여 상전이를 연구하였다. 급속응고 및 열처리된 시편의 미세구조는 X-선 회절 및 투과전자 현미경으로 분석하였다. Al-1.95Nb-0.65Zr, Al-1.3Nb-1.3Zr, 및 Al-0.65Nb-1.95Zr (at%) 3원 합금계를 연구하였다. 각 합금의 조성은 Vegard's 법칙을 적용하여 Al(${\alpha}$)의 기지조직과 $L1_2-Al_3(Nb,Zr)$의 석출상들이 정합을 이루도록 선택되었다. 급속응고된 후 각 합금은 과고용된 Al(${\alpha}$)의 고용상을 형성하였다. Al-1.3Nb-1.3Zr, 및 Al-0.65Nb-1.95Zr의 급속응고된 상태의 시편을 698K에서 열처리하여 알루미늄 기지와 정합의 계면을 갖는 $L1_2-Al_3(Nb_{0.5}Zr_{0.5})$$L1_2-Al_3(Nb_{0.25}Zr_{0.75})$의 상을 각각 석출하였다. 반면 Al-1.95Nb-0.65Zr 합금은 평형상인 $D0_{22}-Al_3(Nb_{0.75}Zr_{0.25})$ 상을 석출하였다. 준안정상의 정합 $Al_3(Nb,Zr)$ 미세 분산상 석출은 입자의 조대화를 억제하고 재료의 고온 강도를 증가될 것으로 사료된다.

Numerical Study on Thermal Deformation of AC4C and AC7A Casting Material (AC4C와 AC7A 주조재의 열변형 수치해석적 연구)

  • Yoon, Hee-Sung;Oh, Yool-Kwon
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.20 no.5
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    • pp.541-546
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    • 2011
  • This study was numerically investigated on thermal deformation of AC4C and AC7A aluminum alloy casting material for manufacturing the automobile tire mold. The metal casting device was used in order to manufacture the mold product of automobile tire at the actual industrial field. The temperature distribution and the cooling time of these materials were numerically calculated by finite element analysis. Thermal deformation with stress distribution was also calculated form the temperature distribution results. The thermal deformation was closely related to the temperature difference between the surface and inside of the casting. As shown by numerical analysis result, the thermal deformation of AC7A casting material became higher than AC4C casting material. In addition, the results of displacement and stress distributions appeared to be larger at the center parts of casting than on its sides because of the shrinkage caused by the cooling speed difference.

Extrusion Die Development of Interior & Exterior Parts for High Speed Train on Aluminum Alloys and Controls of Extrusion Conditions (고속전철 내·외장재용 알루미늄 합금의 압출 금형 개발 및 압출 조건의 제어)

  • Kim, Kee Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.7
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    • pp.50-55
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    • 2018
  • The important thing in extrusion technology is the design and production of molds. Appropriate design of the molds is essential for achieving the desired extrusion of molds at the same time to maximize the life of the molds and increase their efficiency. The extrusion temperature and extrusion speed are the main parameters at the time of extrusion. Different extrusion conditions should be added depending on the extrusion ratio, physical properties of the material, and type of extrusion. In this study, the extrusion process of various 6xxx series aluminum cast alloys for high speed train interior or exterior parts were investigated. The extruded die design was performed for the 6063, 6061, 6N01, 6005, 5083 and 6060 alloy profiles and an extrusion test was conducted. In addition, the extrusion conditions, such as extrusion pressure following as the billet temperature, extrusion temperature, and materials change, were analyzed. Although the 6063 aluminum alloy can be extruded at the lowest temperature and pressure, the 6061 alloy can be extruded at the highest temperature and pressure. From these results, the successful extruded products were manufactured from these established conditions.

The Effect of Hot Isostatic Pressing on Mechanical Properties of Cast Aluminum Alloy (주조된 AI 합금의 기계적 성질에 미치는 HIP의 영향)

  • Kim, Gi-Tae;Yang, Hun-Cheol;Choe, Jae-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.3
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    • pp.461-470
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    • 2002
  • The present paper investigates the effect of hot isostatic pressing (HIPing) on mechanical properties, e.g., tensile strength, ductility and impact absorption energy of sand and die casted aluminum alloys. After HIPing at various temperatures and pressure conditions, uniaxial tensile test and Izod impact test of the samples were carried out. The experimental results showed improvements in uniaxial tensile strength, elongation and Izod impact toughness of sand casted aluminum alloy, while deterioration of a tensile strength fur die casted aluminum alloy. The effect of HIPing for microstructure of the cast aluminum alloy was also investigated.

A Study on the Characteristic of Gas Pore Formation in Lost Foam Casting of Mg alloy;Comparison with Al alloy (마그네슘 합금의 소실모형주조 시 기포형성 특성에 관한 연구;알루미늄 합금과 비교)

  • Shin, Seung-Ryoul;Han, Sang-Won;Lee, Kyong-Whoan
    • Journal of Korea Foundry Society
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    • v.24 no.3
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    • pp.165-174
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    • 2004
  • The pore formation characteristic of Mg alloy during Lost Foam Casting(LFC) was investigated with reduced pressure test and real casting, which was compared with the results of previous work for Al alloy. Cast Mg alloys in LFC had much lower porosities in comparison with those of Al alloys. Also, the proper pouring temperature gave the minimum porosity like Al alloy although it was higher than that of Al alloys due to the worse fluidity of Mg alloy. The pore formation mechanism of Mg alloy in LFC was similar to that of AI alloy but the critical temperature showing the different mechanism is higher than that of Al alloy as much as $30{\sim}50^{\circ}C$. The result that Mg alloy in LFC had the lower porosity comparing with Al alloy was due to the extra solubility of hydrogen gas although the solubility of Al alloy was easily exceeded by the external sources like pyrolyzed polystyrene products. The mold evacuation gave the lower porosity due to the removal of polystyrene pyrolysis products, and reduced shrinkage defects. Also, there was a proper evacuation pressure that gave a porosity of almost 0vol%. But much higher vacuum degree than this proper pressure caused the severe entrapment of polymer pyrolysis products that gave the large porosity.

A Study of Manufacturing AZ91D Mg Alley Wheel (마그네슘 합금제 휠 제조에 관한 연구)

  • Kim, Jung-Gu;Shin, Il-Seong;Kum, Dong-Hwa
    • Korean Journal of Materials Research
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    • v.9 no.7
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    • pp.715-723
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    • 1999
  • Magnesium has been used as wheel materials in the automotive industry for more than 20 years. The magnesium wheels, which are lighter by 25% than aluminum wheels, provide easy controllability providing excellent road holding by the reduction of weight. The purpose of this work is to develop cast AZ91D alloy wheel by sand cast and permanent mold cast. The fluxless melting with the protective gas $(SF_6+CO_2)$ was Performed to eliminate oxidation of melt and impurity. The transfer of molten magnesium to the mold was done by using gas-pressurized Pump system through the heated pipe. The mechanical properites of AZ91D alloy wheel were investigated as a function of heat treatment, ingot composition.

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Effects of Process and Casting Variables on the Results of Degassing AC4C Aluminum Alloy Melt by Using Rotary Degasser (공정 및 주조 변수의 AC4C 알루미늄 합금 용탕의 로터리 degasser를 이용한 탈가스 처리 결과에 미치는 영향)

  • Lee, Ki-Joon;Kwon, Hae-Wook
    • Journal of Korea Foundry Society
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    • v.20 no.6
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    • pp.407-418
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    • 2000
  • The effect of various factors on the results of degassing of AC4C aluminum alloy melt by using rotary degasser were investigated. The difference between the effects of nitrogen gases of commercial pure and high purity grades on the degassing results was not significant. The optimum degassing condition was obtained. The effect of holding and degassing temperature was not significant, either. The result of degassing was deteriorated by the modification treatment of eutectic silicon, meanwhile improved by the grain refining. The effect of the latter was stronger than that of the former when the melt was treated simultaneously. The volume fractions of hydrogen porosity of the castings obtained from the molds with water moisture such as natural and green sand molds were much higher than those from the molds without that such as pep-set and $CO_2$ molds.

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