• 소성∙가공
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• 제33권1호
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• pp.50-54
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• 2024

In this paper, the process of extruding Cu-10Fe alloy using a finite element analysis (FEA) was theoretically analyzed. To achieve this, the dependence of strain rate and temperature of the alloy required for the extrusion process was secured by utilizing databases for Cu and Fe and the KHL model. For microstructure analysis, FE-SEM with EDS was used to distinguish the phases present in Cu-10Fe alloy. The mechanical characteristics of Cu-10Fe alloy were secured using the results of fitting the mechanical properties of Copper and Steel from the Deform database to the KHL model. The deformation behavior within the alloy during hot extrusion was analyzed, providing insights into effective stress, effective strain, effective strain rate, and temperature. It was observed that the strain distribution was non-uniform. These research findings contribute to an improved understanding of the hot extrusion process of Cu-10Fe alloy and can aid in predicting the mechanical properties of the material.

• Applied Microscopy
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• 제45권1호
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• pp.9-15
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• 2015

In the present study, microstructural evolution in CuCrFeNi, CuCrFeNiMn, and CuCrFeNiMnAl alloys has been investigated. The as-cast CuCrFeNi alloy consists of a single fcc phase with the lattice parameter of 0.358 nm, while the as-cast CuCrFeNiMn alloy consists of (bcc+fcc1+fcc2) phases with lattice parameters of 0.287 nm, 0.366 nm, and 0.361 nm. The heat treatment of the cast CuCrFeNiMn alloy results in the different type of microstructure depending on the heat treatment temperature. At $900^{\circ}C$ a new thermodynamically stable phase appears instead of the bcc solid solution phase, while at $1,000^{\circ}C$, the heat treated microstructure is almost same as that in the as-cast state. The addition of Al in CuCrFeNiMn alloy changes the constituent phases from (fcc1+fcc2+bcc) to (bcc1+bcc2).

• 한국주조공학회지
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• 제41권1호
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• pp.3-10
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• 2021

알루미늄 합금과 주철의 복합주조 공정 중에는 주철로부터 철 성분이 용해되어 알루미늄 용탕에 혼입될 수 있으므로 다양한 Fe함유 금속간 화합물이 형성되며, 이로 인해 알루미늄 합금의 인장 특성이 크게 저하 될 수 있다. 반면 불순물로 첨가되는 Fe와 는 달리 Cu의 경우 알루미늄 합금의 기계적 물성을 향상시키기 위해 첨가되는 합금원소이다. 본 연구에서는 Fe와 Cu의 첨가로 인한 알루미늄 합금의 미세조직 및 인장특성의 변화를 조사하였다. 첨가된 Fe 함량이 1% 이상일 경우 조대한 Al₅FeSi 상과 같은 Fe 함유 화합물들이 다량 형성되어 인장 특성이 현저히 감소하는 것으로 나타났다. Cu가 첨가 된 알루미늄 합금의 경우 Al2Cu 상이 추가로 형성되었으며, 인장 강도가 뚜렷하게 향상되는 결과를 보였다.

• 한국결정성장학회지
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• 제28권4호
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• pp.175-178
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• 2018

구리 금속은 높은 열전도도로 heat sink 혹은 heat exchanger로 널리 사용되고 있다. 그러나 이에 반하여 낮은 인장강도와 사용온도 한계를 가지고 있다. 따라서 높은 열전도도, 낮은 제작비와 함께 우수한 기계적 특성이 요구된다. 본 연구에서는 이를 위하여 동철합금($Cu_{50}-Fe_{50}$ alloy)를 고주파 가열로를 이용하여 제조하고 그 특성을 조사하였다. 제조된 동철합금은 Cu, ${\alpha}$-Fe, ${\gamma}$-Fe 결정구조를 기진 dendrite 미세구조를 보여주었다. 제조된 동철합금은 XRD, FE-SEM, EDS 및 XRF를 이용하여 결정구조 및 미세구조를 분석하였으며 전력공급 접점용 소재로서의 적합성을 확인하고자 하였다.

• 한국군사과학기술학회지
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• 제14권6호
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• pp.1018-1025
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• 2011

The improved properties of corrosion for 90Cu10NiFe alloy in natural seawater were explained by sodium diethyl dithio carbamate(NaDDC), namely organic compound, which is reagent for heavy metal extractions of waste water. The efficiency of NaDDC as corrosion inhibitor for 90Cu10NiFe alloy has been investigated in seawater after immersion in various concentrations of NaDDC solutions for 12~36hrs at pH 8.2 by weight loss test and electrochemical techniques including potentiodynamic polarization and SEM-EDS measurements. The results showed that the corrosion resistance of 90Cu10NiFe alloy improves with the increasing concentration of NaDDC but it did not improves with increasing time any more, so the highest inhibition efficiency was 93% at 100mg/L, 36hrs. The results obtained from weight losses and corrosion rates in polarization curve measurements were in good agreement. Therefore, it showed that NaDDC is a good inhibitor for copper corrosion of 90Cu10NiFe alloy.

• Metals and materials international
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• 제24권6호
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• pp.1275-1284
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• 2018

A rotating magnetic field (RMF) was applied in the solidification process of Cu-8Fe alloy. Focus on the mechanism of RMF on the solid solution Fe(Cu) atoms in Cu-8Fe alloy, the influences of RMF on solidification structure, solute distribution, and material properties were discussed. Results show that the solidification behavior of Cu-Fe alloy have influenced through the change of temperature and solute fields in the presence of an applied RMF. The Fe dendrites were refined and transformed to rosettes or spherical grains under forced convection. The solute distribution in Cu-rich phase and Fe-rich phase were changed because of the variation of the supercooling degree and the solidification rate. Further, the variation in solute distribution was impacted the strengthening mechanism and conductive mechanism of the material.

• Advances in materials Research
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• 제2권4호
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• pp.221-235
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• 2013

To obtain bronze with good mechanical properties and high wear resistance, a new bronze (CADZ) is proposed on the basis of various fundamental information. The CADZ consists of the elements Al10.5, Fe4.2, Sn3.7 and Ni3.1, and its design is based on Cu-Al10.5 alloy. The Cu-10.5%Al is very hard and brittle. To obtain the high material ductility of the Cu-10.5%Al alloy, an attempt was made to add a few percent of Sn. Moreover, to make high strength of the Cu alloy, microstructure with small grains was created by the proper amount of Fe and Ni (Fe/Ni = 0.89). The mechanical properties of the CADZ sample have been examined experimentally, and those were compared with commercial bronzes. The tensile strength and wear resistance of CADZ are higher than those for commercial bronzes. Although the ductility of CADZ is the lower level, the strain to failure of CADZ is about 2.0~5.0% higher than that for the Cu-Al10.5 alloy. Details of the microstructural effects on the mechanical properties in the CADZ sample were further discussed using various experimental results.

• 한국분말재료학회지
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• 제11권6호
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• pp.486-492
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• 2004

We report the crystallization and magnetic properties of non-equilibrium $Al_{0.6}(Fe_{x}Cu_{1-x})_{0.4}(x=0.25, 0.50, 0.75)$ alloy powders produced by rod-milling as well as by new chemical leaching. X-ray diffractometry, transmission electron microscopy, differential scanning calorimetry and vibrating sample magnetometry were used to characterize the as-milled and leached specimens. After 400 h or 500 h milling, only the broad peaks of nano bcc crystalline phases were detected in the XRD patterns. The crystallite size, the peak and the crystallization temperatures increased with increasing Fe. After being annealed at $600{^\circ}C$ for 1 h for as-milled alloy powders, the peaks of bcc $AlCu_{4}\;and\;Al_{13}Cu_{4}Fe_{3}\;for\;x=0.25,\;bcc\;AlCu_{4}\;and\;Al_{5}Fe_{2}\;for\;x=0.50,\;and\;Al_{5}Fe_{2},\;and\;Al_{0.5}Fe_{0.5}\;for\;x=0.75$ are observed. After being annealed at $500{^\circ}\;and\;600{^\circ}C$for 1 h for leached specimens, these non-equi-librium phases transformed into fcc Cu and $CuFe_{2}O_{4}$phases for the x=0.25 specimen, and into bcc ${\alpha}-Fe,\;fcc\;Cu,\;and\;CuFe_{2}O_{4}$ phases for both the x=0.50 and the x=0.75 specimens. The saturation magnetization decreased with increasing milling time for $Al_{0.6}(Fe_{x}Cu_{1-x})_{0.4}$ alloy powders. On cooling the leached specimens from $800{\~}850^{\circ}C$,\;the magnetization first sharply increase at about $491.4{\circ}C,\;745{\circ}C,\;and\;750.0{\circ}C$ for x=0.25, x=0.50, and x=0.75 specimens, repectively.

• 한국자기학회지
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• 제5권1호
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• pp.38-41
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• 1995

$\alpha$-Fe를 주상으로 하는 새로운 Nd-Fe-B계 합금을 개발하기 위하여 Nd 함유량을 4at.%로 고정시킨 Nd-Fe-B 초미세결정립합금의 제조 및 자기특성이 조사되었다. 급속응고법으로 제조된 $Nd_{4}Fe_{85.5}B_{10.5}$ 비정질합금은 결정화하여 $\alpha$-Fe 기지상에 $Nd_{2}Fe_{14}B$이 형성되나 자기특성${_{i}H_{c}=95.5kA/m(1.2kOe),\;Br=1.2T}$은 열화된다. Nb 및 Cu를 첨가한 $Nd_{4}Fe_{82}B_{10}Nb_{3}Cu_{1}$ 합금은 $\alpha$-Fe 결정립미세화(<30nm)로 보자력이 207kA/m(2.6 kOe)로 증가하나 잔류자화는 개선되지 않았다. 이 합금조성에 8at.% Co 첨가는 결정립을 더욱 미세화시키며 자기특성을 개선 시킨다. 최적열처리조건에서 $Nd_{4}Fe_{74}Co_{8}B_{10}Nb_{3}Cu_{1}$ 합금의 잔류자화, 보자력 및 최대에너지적이 각각 1.34 T, 219 kA/m (2.75kOe) 및 $95.5kJ/m^{3}$(12MGOe) 이다.

• 한국분말재료학회지
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• 제26권2호
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• pp.112-118
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• 2019

Infiltration is a popular technique used to produce valve seat rings and guides to create dense parts. In order to develop valve seat material with a good thermal conductivity and thermal expansion coefficient, Cu-infiltrated properties of sintered Fe-Co-M(M=Mo,Cr) alloy systems are studied. It is shown that the copper network that forms inside the steel alloy skeleton during infiltration enhances the thermal conductivity and thermal expansion coefficient of the steel alloy composite. The hard phase of the CoMoCr and the network precipitated FeCrC phase are distributed homogeneously as the infiltrated Cu phase increases. The increase in hardness of the alloy composite due to the increase of the Co, Ni, Cr, and Cu contents in Fe matrix by the infiltrated Cu amount increases. Using infiltration, the thermal conductivity and thermal expansion coefficient were increased to 29.5 W/mK and $15.9um/m^{\circ}C$, respectively, for tempered alloy composite.