• Title/Summary/Keyword: Fe-Si alloy

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A Study on the Microstructure and Adhesion Properties of Sn-3.5Ag/Alloy42 Lead-Frame Solder Joint (Sn-3.5Ag/Alloy42 리드프레임 땜납접합의 미세조직과 접합특성에 관한 연구)

  • Kim, Si-Jung;Bae, Gyu-Sik
    • Korean Journal of Materials Research
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    • v.9 no.9
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    • pp.926-931
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    • 1999

  • The microstructure, wettability, shear strength and aging effect of Sn-3.5Ag/Cu and Alloy42 lead-frame solder joints were measured for comparison. In the case of Sn-3.5Ag/Cu, $Ag_3Sn and Cu_6Sn_5$ phases in the matrix Sn and $1~2\mu\textrm{m}$ thick $Cu_6Sn_5$ phase at the interface of solder/lead-frame were formed. In the case of Sn-3.5Agl Alloy42, only AgJSn phase of low density in the matrix Sn and $0.5~1.5\mu\textrm{m}$ thick $FeSn_2$, phase at the interface of solder/leadframe were formed. Comparing to Cu, Alloy42 showed wider area of spread and smaller contact angle, thus better wet­tability. But shear strength and ductility of Alloy 42 solder joints were only 33% and 75% of those of Cu, respectively After aging at $180^{\circ}C$ for 1 week, $\xi-Cu_3Sn$ layer on $\eta-Cu_6Sn_5$ layer was formed on Cu lead-frame, while coarsened cir­cular $Ag_3Sn$ phase in the matrix and thickened $FeSn_2$, at the interface were formed on Alloy42 lead- frame.

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Manufacture of 7000 Al Alloy with Superior Extrudability and Its Extrusion Limit Diagram (압출성 향상을 위한 고강도 7000계 알루미늄 합금의 제조 및 압출한계선도)

  • Ham, H.W.;Kim, B.M.;Cho, H.;Cho, H.H.
    • Transactions of Materials Processing
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    • v.8 no.5
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    • pp.482-490
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    • 1999

  • 7000 series Al alloy with good mechanical properties has been focused with tendency to reduce the components weight of aircraft and automobile. However, it is difficult to manufacture a sound extruded product because of segregation, grain growth, casting defect, surface defect, decreasing extrudability and so on. The objective of this study is to manufacture a new 7000 al alloy more than the extrudability of A7N01 and A7003 through controlling the weight (%) Mg, Zn, Si. Hot extrusion experiments on the axisymmetric rod are performed in 500℃ and also performed analysis of the same process using unmerical analysis method, a coupled rigid-thermoviscoplastic finite element method. Extrusion limit diagram was obtained for the developed alloy by FE-simulation in order to define the relationship of extrusion speed and initial billet temperature.

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The Effects of Insulating Materials on the Magnetic Properties of Nanocrystalline FeCuNbSiB Alloy Powder Cores (FeCuNbSiB 나노결정립 합금 분말코아의 자기적 특성에 미치는 절연체의 영향)

  • Noh, T.H.;Choi, H.Y.
    • Journal of the Korean Magnetics Society
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    • v.14 no.5
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    • pp.186-191
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    • 2004

  • The variation of magnetic properties with insulating materials(glass frits, talc and polyamide) in compressed powder cores composed of Fe$\sub$73.5/Cu$_1$Nb$_3$Si$\sub$15.5/B$\sub$7/ nanocrystalline alloy powders(size: 250～850 $\mu\textrm{m}$) and 3 wt% insulators has been investigated. Larger permeability was obtained at the frequency lower than 300～400 kHz for the powder cores including ceramic insulators(glass frits and talc) as compared to the cores with polyamide, while at higher frequency than 1 MHz the permeability of the former cores decreased rapidly. Further the cores with ceramic insulators showed larger core loss and smaller peak quality factor attained at lower frequency. On the contrary, the powder cores with polyamide exhibited high stability of permeabilities up to several MHz and superior core-loss and quality-factor properties. Moreover the dc bias property was better in the wide field range for the cores having polyamide. The enhanced magnetic properties of polyamide-added cores were attributed to the more sufficient electrical insulation between magnetic particles, where the higher insulation state was considered to be obtained from the larger volume fraction of polyamide in the powder cores.

  • https://doi.org/10.4283/JKMS.2004.14.5.186 인용 PDF KSCI

Characteristic Evaluation of the Fe-Al Alloy Preform Fabrication by Reactive Sintering Process for the Al Matrix Composites. (반응소결법으로 제조한 Al기 복합재용 Fe-Al합금 예비성형체의 특성평가)

  • Choi, Dap-Chon;Park, Sung-Hyuk;Joo, Hyung-Gon
    • Journal of Korea Foundry Society
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    • v.19 no.6
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    • pp.493-500
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    • 1999

  • Squeeze casting was used for fabricating a light metal base composite having high strength and wearresistance. Reactive sintering was used to prepare the preform of Squeeze casting. To utilize Fe-Al intermetallic compounds and SiC particle as a reinforcement, there needs to prepare Fe-Al mixed powder at 50, 60, 70at.%Al, and add SiC powder to the above mixture at 4, 7, 16, 24wt.%. The prepared mixture with SiC was reactive sintered in a tube furnace at $660^{\circ}C$ to get a porous hybrid preform of intermetallic compound and SiC. The preform prepared above was placed in a metal mold, preheated at $660^{\circ}C$ AC4C matrix was injected into the mold with the temperature of the melt at $610^{\circ}C$ After these processes, 66MPa was applied to the mold for 5 minute to finish the whole procedure. The maximum reaction temperature was increased with the increased Al amount, but decreased with the increased SiC amount. The density of the preform was decreased with SiC amount increase in the compacts due to swelling of the preform. An optical microscope was applied to observe the micro structure and the dispersion of the reinforcements. To analyze phases, We utilized XRD, EDS. Hardness test were chosen to get the information of mechanical properties. There were no significant changes in micro structure between the composite and preform. However, it was shown that uniform dispersion of the reinforcers and complete infiltration of the melt into the preform were achieved through the procedure of the squeeze casting. It was observed that the hardness of the composite is decreased with increased SiC amount, resulting from the volumetric expansion of the preform.

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