• Title/Summary/Keyword: AlSiCu

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Corrosion of High Strength and High Ductility Al-Mg Develpment Aluminum Alloy (고강도, 고연성 Al-Mg계 알루미늄 개발 합금의 내식성 특성)

  • Choe, In-Gyu;Kim, Si-Myeong;Kim, Sang-Ho
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.05a
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    • pp.155-156
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    • 2015
  • 최근 자동차 및 항공기의 경량화 관련하여 알루미늄 합금의 필요성이 높아지고 있으나, 자동차재료에 쓰이는 알리미늄 합금의 경우 높은 이온화 경향 때문에 Fe, Cu, Pb 등과 접촉하면 쉽게 부식되는 단점이 있다. 본 연구에서는 기존의 Magsimal-59 샘플과 본 연구에서 개발한 고용질, 저용질 Duplex 알루미늄 합금과의 내식성을 분극 및 갈바닉을 통해 확인하고, 균질화처리를 통해 내식성을 개선한다.

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Evaluation of the Residual Stress with Respect to Supporting Type of Multi-layer Thin Film for the Metallization of Pressure Sensor (압력센서의 배선을 위한 다층 박막의 지지조건 변화에 따른 잔류응력 평가)

  • Shim, Jae-Joon;Han, Geun-Jo;Han, Dong-Seup
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.5
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    • pp.532-538
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    • 2004
  • MEMS technology applying to the sensors and micro-electro devices is complete system. These microsystems are made by variable processes. Especially, the mentallization process has very important functions to transfer the power operating the sensor and signal induced from sensor part. But in the structures of MEMS the local stress concentration and deformation are often yielded by an irregular geometrical shape and different constraint. Therefore, this paper studies the effect of supporting type and thickness ratio about thin film of the substrate on the residual stress variation when the thermal loads is applied to the multi-layer thin film fabricated by metallization process. Specimens were made from several materials such as Al, Au and Cu. Then, uniform thermal load was applied, repeatedly. The residual stress was measured by FE Analysis and nano-indentation method using AFM. Generally, the specimen made of Al induced the larger residual stress than that of made of other materials. Specimen made of Cu and Au having the low thermal expansion coefficient induces the minimum residual stress. Similarly, the lowest indentation length was measured by nano-indentation method in the Si/Au/Cu specimen. Particularly, clusters are created in the specimen made of Cu by thermal load and the indentation length became increasingly large by cluster formation.

Investigation of X-ray-induced Defects on Metals and Silicon by Using Coincidence Doppler Broadening Positron Annihilation Spectroscopy

  • Lee, C.Y.
    • Journal of the Korean Physical Society
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    • v.73 no.12
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    • pp.1895-1898
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    • 2018
  • The mechanical properties of Al, Ti, Fe, and Cu metals p-type Si, and n-type Si were investigated by using coincidence Doppler broadening (CDB) positron annihilation spectroscopy. The samples in this experiment were irradiated by using X-rays at generating powers for up to 9 kW. The data taken after the irradiation showed all the characteristic features predicted from defects with vacancies. The S parameter values of the metals were generally less than those of semiconductors such as p-type Si and n-type Si. The relationship between n-type Si and p-type Si were more affected when n-type Si rather than p-type Si was irradiated with X-rays.

Effects of Coating Materials on Fluidity and Temperature Loss of Molten Metals from Runner Systems in Full Moulds.

  • Cho, Nam-Don;Kim, Yong-Hyun;Choi, Jung-Kwon
    • Journal of Korea Foundry Society
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    • v.10 no.1
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    • pp.31-42
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    • 1990
  • The full mould casting process in one of the newly developed techniques which has many advantages. Unbonded sand mould has been prepared for the major mould and $CO^2$ gas mould has been used occasionally for comparison. Patterns were built up with expanded polystyrene and coated with three different materials. Silica, graphite and zircon were used for the coating layer. The effects on fluidity and temperature loss of molten metals were investigated. The molten metals were Al-5% Si alloy, Cu-30% Zn alloy and gray iron of approximately 4.0% of carbon equivalent. Experimental variables were runner section area, superheat, sprue height, coating materials, coating thickness and apparent density of EPS pattern. The effects of coating materials on fluidity and temperature loss of the molten metals during transient pouring are summarized as follows : As runner section area, superheat and sprue height increased, fluidity increased. Temperature loss decreased as runner section area and sprue height increased. However, reversed effects were observed in the case of superheat increment. The coating materials decreased the fluidity of each alloy in the order of silica, graphite and zircon. Zircon brought to the highest temperature loss among the coating materials used. The fluidity increased in the order gray iron, Cu-30% Zn and Al-5% Si alloy while temperature loss in the reverse order. Especially in case of reduced pressure process, the fluidity was increased apparently. Al-5% Si alloy showed the lowest temperature loss among the alloys. The increment of the apparent density of EPS pattern resulted in the fluidity decrease and temperature loss increase. The relation between fluidity and temperature loss of each alloy can be expressed by the following equation within the coating thickness limit of 0.5-1.5㎜. F^*={\frac{a}{T^*-b}}-c$ where, $F^*$ : fluidity in the Full mould, $T^*$ : temperature loss in the mould. a : parameter for full mould. b, c : constants.

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Seasonal Variation and Statistical Analysis of Particulate Pollutants in Urban Air (도시대기립자상물질중 오염성분의 계절적 변동 및 통계적 해석)

  • 이승일
    • Journal of environmental and Sanitary engineering
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    • v.9 no.2
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    • pp.8-23
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    • 1994
  • During the period from Mar., 1991 to Feb., 1992 66 tSP samples were collected by Hi volume air sampler at 1 sampling site in Seoul and the amount of concentration of 21 components(SO$_{4}$$^{2-}$, NO$_{3}$$^{-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Al, Ba, Ca, Cd, Cr, Cu, Fe, It Mg, Mn, Na, Ni, Pt Si, Ti, Zn, Zr ) were measured. And monthly and seasonal variation were surveyed and the principal component analysis( PCA ) were carried out with respect to these amount of pollutants, minimum of visibility and radiation on a horizontal surface. The total amount of soluble ion in water was high in order o(SO$_{4}$$^{2-}$> NO$_{3}$$^{-}$> N%'>Cl$^{-}$ and metal ion was high in order of Na> Ca>Si> Fe> Al> K> Mg> Zn> Pb> Cu>Ti> Mn > Ba> Cr> Zr> Ni> Cd. There was Seasonal variation in concentration for SO$_{4}$$^{2-}$, NH$_{4}$$^{+}$, Cl$^{-}$, Na, Al, Ca, Bt Mg, Fe and Si. It was assumed that the components of the highest concentration on April were depend on yellow sand and the frequency of wind velocity and direction. As the results of PCA, the amount of pollution components was able to characterized with two principal components(Z$_{1}$, Z$_{2}$ ). The first principal components Z$_{1}$ was considered to be a factor indicating the pollutants originated from natural generation and The second principal components Z$_{2}$ was considered to be a factor indicating the pollutants originated from human work. The monthly concentration of pollutants in ISP, minimum of visibility and radiation on a horizontal surface was possible to evaluate by the use of these two principal components Z$_{1}$ and Z$_{2}$ .

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Adsorption Behaviors of Metal Elements onto Illite and Halloysite (일라이트, 할로이사이트에 대한 중금속 원소의 흡착특성)

  • 추창오;김수진;정찬호;김천수
    • Journal of the Mineralogical Society of Korea
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    • v.11 no.1
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    • pp.20-31
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    • 1998
  • Adsorption of metal elements onto illite and halloysite was investigated at $25^{\circ}C$ using pollutant water collected from the gold-bearing metal mine. Incipient solution of pH 3.19 was reacted with clay minerals as a function of time: 10 minute, 30 minute, 1 hour, 12 hour, 24 hour, 1 day, 2 day, 1 week, and 2 week. Twenty-seven cations and six anions from solutions were analyzed by AAs (atomic absorption spectrometer), ICP(induced-coupled plasma), and IC (ion chromatography). Speciation and saturation index of solutions were calculated by WATEQ4F and MINTEQA2 codes, indicating that most of metal ions exist as free ions and that there is little difference in chemical species and relative abundances between initial solution and reacted solutions. The adsorption results showed that the adsorption extent of elements varies depending on mineral types and reaction time. As for illite, adsorption after 1 hour-reaction occurs in the order of As>Pb>Ge>Li>Co, Pb, Cr, Ba>Cs for trace elements and Fe>K>Na>Mn>Al>Ca>Si for major elements, respectively. As for halloysite, adsorption after 1 hour-reaction occurs in the order of Cu>Pb>Li>Ge>Cr>Zn>As>Ba>Ti>Cd>Co for trace elements and Fe>K>Mn>Ca>Al>Na>Si for major elements, respectively. After 2 week-reaction, the adsorption occurs in the order of Cu>As>Zn>Li>Ge>Co>Ti>Ba>Ni>Pb>Cr>Cd>Se for trace elements and Fe>K>Mn>Al, Mg>Ca>Na, Si for major elements, respectively. No significant adsorption as well as selectivity was found for anions. Although halloysite has a 1:1 layer structure, its capacity of adsorption is greater than that of illite with 2:1 structure, probably due to its peculiar mineralogical characteristics. According to FTIR (Fourier transform infrared spectroscopy) results, there was no shift in the OH-stretching bond for illite, but the ν1 bond at 3695 cm-1 for halloysite was found to be stronger. In the viewpoint of adsorption, illite is characterized by an inner-sphere complex, whereas halloysite by an outer-sphere complex, respectively. Initial ion activity and dissociation constant of metal elements are regarded as the main factors that control the adsorption behaviors in a natural system containing multicomponents at the acidic condition.

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Adhesion Properties of Cu/cordierite for Multilayer IC Packaging (다층 IC펙키지용 구리/코디에라이트 접합 특성)

  • Han, Byeung-Sung;Yu, Sung-Tae;Lim, Nam-Hi;Jang, Me-Hea;Park, Sung-Jin
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.10
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    • pp.96-100
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    • 1990
  • The cordierite ($2MgO,2Al_{2}O_{3},5SiO_{2}$) is of great interest for packaging substrates of multilayer IC. The Cu layer was fabricated on the cordierite substrate by the screen printing method and the adhesion properties of the interfaces at the different cosintering conditions were studied. When cosinted in the $Ar+H_{2}O$atmosphere good adhesion was obtained and the heating was found out to be an important factor for the adhesion.

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Bending Behaviors of Stainless Steel Tube Filled with Al5Si4Cu4Mg Closed Cell Aluminum Alloy Foam (발포 Al5Si4Cu4Mg 알루미늄 합금이 충진된 304 스테인리스강 원통의 굽힘저항 특성)

  • Kim, Am-Kee;Lee, Hyo-Jin;Cho, Seong-Seock
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.10
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    • pp.1686-1694
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    • 2003
  • The foam-filled tube beams can be used for the front rail and firewall structures to absorb impact energy during frontal or side collision of vehicles. In the case of side collision where bending is involved in the crushing mechanism, the foam filler would be effective in maintaining progressive crushing of the thin-walled structures so that much impact energy could be absorbed. In this study, bending behaviors of the closed-cell-aluminum-alloy-foam-filled stainless steel tube were investigated. The various foam-filled specimens including piecewise fillers were prepared and tested. The aluminum-alloy-foam filling offered the significant increase of bending resistance. Their suppression of the inward fold formation at the compression flange as well as the multiple propagating folds led to the increase of load carrying capacity of specimens. Moreover, the piecewise foams would provide the easier way to fill the thin-walled shell structures without the drawback of strength.

A Study on the Mechanical Properties of Al-8.6% Si-3.6% Cu Alloy Cast in Plaster Mold (석고주조(石膏鑄造)한 Al-8.6% Si-3.6% Cu 합금(合金)의 기계적(機械的) 성질(性質)에 관(關)한 연구(硏究))

  • Yeo, In-Dong;Kim, Dong-Ok;Kang, In-Chan
    • Journal of Korea Foundry Society
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    • v.4 no.4
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    • pp.5-13
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    • 1984
  • This paper is presented for showing the effect of cooling rate on dendrite arm spacing, correlated with the chilling power of molding materials (conventional plaster, foamed plaster, silica sand) and section thickness, and also showing relationship between dendrite arm spacing and mechanical properties for an aluminum - 8.6 percent silicon - 3.6 percent copper alloy. Local solidification time $(t_f)$ and secondary dendrite arm spacing (d) could be varied widely in accordance with the molding materials and casting thickness, and the following relationship is obtained: $d=9.4t_f\;^{0.31}$ A good correlation between dendrite arm spacing and mechanical properties such as ultimate tensile strength, yield strength, hardness was found, that is, mechanical properties decreased in a linear manner with increase in log of secondary dendrite arm spacing. Ultimate tensile strength in conventional plaster mold casting decreased by 15 percent comparing with the sand casting, where as in foamed plaster mold casting, it decreased by 30 percent comparing with the sand casting. From those results, it has been verified that DAS might be the most representative parameter for predicting mechanical properties varing with the different cooling condition.

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Chemical Analysis of Fly Ashes from Municipal Solid Waste Incinerators (생활폐기물 처리시설 배출 비산재의 조성분석)

  • Jang, Seong-Ki;Choi, Duk-Il;Lim, Chang-Ho;Lee, Jin-Sook
    • Analytical Science and Technology
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    • v.13 no.2
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    • pp.215-221
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    • 2000
  • Analysis of fly ashes from the MSW incinerators was carried out using XRF, ICP-MS and ICP-AES. It was found that the major elements of fly ash were Ca, K, Na, Si, Al, S, Cl and O by the XRF analysis. The XRD spectra showed that the fly ashes were mainly consisted with the chlorides, hydroxides, carbonates and also oxides of former elements. For the determination of minor elements such as Zn, Pb, Cu, Cr, and Cd, we used ICP-AES and ICP-MS after microwave digestion and the results were compared with the result of XRF.

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