• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1165-1167
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• 1995

The Cu-Si alloy has been proposed as a new matrix materal for filamentary Nb-Ti wires in AC use. The Cu-Si alloy shows approprite mechanical and electrical properties, and is economically more favourable than the Cu-Ni alloy matrix used currently. Moreover, the addition of Si to Cu prevents the formation of intermetallic compounds around the filaments. After we investigated resistivity and hardness of Cu-Si alloy as matrix materal, investigated CuSi/NbTi interface reactions and superconductivities of superconducting wires that were made by various heat treatment.

• 한국표면공학회지
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• 제29권4호
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• pp.278-285
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• 1996

The structure of coating layer formed by hot dip Al-Cu alloy coating on Monel 1400 metal was studied. The coating layer consists of alloyed layer adjacent to the Monel 400 substrate and Al-Cu alloy. It was found that the hardness of coating increased with dipping time and heat treatment associated with the diffusion and the formation of intermetallic compound at the interface. However the thickness of coating layer was decreased at high dipping temperature due to tile higher viscosity of liquid coating alloy. Diffusion heat treatment at $600^{\circ}C$ after coating resulted in the disappearence of adhered Al(Cu) and $CuAl_2$ phases, and then they transformed into the new phases of CuAl and Al7Cu4Ni at coating layer.

• 한국분말재료학회지
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• 제11권3호
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• pp.193-201
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• 2004

1960년 Au-Si계 합금에서 처음으로 비정질상이 급속 응고법에 의해 보고된 이래/sup 1)/ 지난 40년 간 많은 합금계에서 비정질상이 보고되어졌다. 대표적으로 Fe-, Ni-, Co기 합금 등 많은 합금계에서 비정질상이 보고되었으나, 비정질상의 형성을 위해서는 약 105 K/s이상의 높은 냉각속도를 필요로 하였다. 1980년대 수백 K/s의 낮은 냉각속도 하에서도 비정질상이 형성될 수 있는 다원계 합금(multi-component alloy)이 Mg-Ln-(Ni, Cu, Zn), Ln-Al-TM 합금에서 보고되어 졌으나 많은 관심을 받지 못하다가 1993년 Zr-Ti-Ni-Cu-Be 합금에서 수 ㎝ 크기의 비정질합금 제조가 보고되면서 전 세계적으로 많은 관심을 받게 되었다. Zr-Ti-Ni-Cu-Be계 벌크 비정질 합금이 보고된 후 Zr-(Nb,Pd)-Al-TM, Pd-Cu-Ni-P, Fe-Co-Zr-Mo-W-B, Ti-Zr-Ni-Cu-Sn등 여러 합금계에서 벌크 비정질 합금이 보고되었다. (중략)

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.24-26
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• 2003

We fabricated Ni and Ni alloy substrates for YBCO coated conductors. The Ni and Ni alloy substrate was fabricated by powder metallurgy technique and cold rolling. The texture of substrates had a strong 4-fold symmetry and ［111］∥ND texture after annealing temperature of 100$0^{\circ}C$. The measured full-width half-maximum (FWHM) of in-plane and out-of-plane was in the range of 6$^{\circ}$-10$^{\circ}$. The powder metallurgy technique is fabrication of the substrates for considered to be suitable for the application of YBCO coated conductors.

• 열처리공학회지
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• 제12권2호
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• pp.145-156
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• 1999

The distribution of the second phase, the change of transformation temperature and mechanical properties with thermomechanical treatment conditions were investigated by metallography, calorimetry, EDS, tensile test and fractography in a Cu-Al-Ni-Ti-Mn alloy. The cast structure revealed Ti-rich precipitates($X_L$ phase) between dendrite arms, which have been identified as $(Cu,Ni)_2TiAl$ intermetallic compounds. By homogenizing above $900^{\circ}C$, the $X_L$ phase was melted in the matrix, while the Xs phase was precipitated in matrix and the volume fraction of it was increased. When hot-rolled specimen was betatized below $750^{\circ}C$, recrystallization could not be observed. However, the specimen betatized above $800^{\circ}C$ was recrystallized and the grain size was about $50{\mu}m$, while Xs phase was precipitated in matrix. With raising betatizing temperature, $M_s$ and $A_s$ temperatures were fallen and transformation hysteresis became larger. The strain of the specimen betatized at $800^{\circ}C$ was 8.2% as maximum value. The maximum shape recovery rate could be obtained in the specimen betatized at $800^{\circ}C$ but it was decreased due to the presence of Xs phase with increasing betatizing temperature.

• Journal of Welding and Joining
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• 제5권4호
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• pp.47-53
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• 1987

The purpose of this study is to reexamine our test method in the light ofstatistical methods for data interpretation. Our trial to apply Plackett-Burman statistical model in multifactorial welding experiments shows that is saves much time and cost and extracts very accurate results. In this study, the parametric effects of bead shape on pulse MIG process in Cu-Ni alloy are investigated for verifying our trial.

• 한국표면공학회지
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• 제22권4호
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• pp.179-184
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• 1989

This study seeks to the morphological changes in the oxide skin of the Al-10wt.%si alloy melts. These changes depend on the oxidation time and the temperature of the molten alloy, as well as the effects of adding Mg, Cu and Ni. Thess affects observed by X-ray diffractometer(XRD) and scanning electron microscope(SEM)' Very litte oxide skins on Al-10wtwt.%Si alloy melts can be detected by XRD because it is less than the measuring capabillity of the XRD, or the formation of noncrystalline oxide skins oxide skins canbe deteced by SEM. The addition of 1%Mg and 1%Cu-1%Mg-2.5%Ni to this base alloy crystallized the structure of the oxide skins and increased the oxidation in proportion to the length of time, but adding 3% had hardiy anyaffect at all on the crystal structure of the oxide skins.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.725-728
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• 2001

We have fabricated thin films using the DC/RF magnetron sputtering of 74wt%Ni-l8wt%Cr-4wt%Al-4wt%Cu alloy target and studied the effect of the process parameters on the electrical properties for low TCR(Temperature Coefficient of Resistance) films. In sputtering process, pressure, power and substrate temperature, are varied as controllable parameter. The films are annealed to 400$^{\circ}C$ in air and nitrogen atmosphere. The sheet resistance, TCR of the films increases with increasing annealing temperature. It abruptly increased as annealing temperature increased over 300$^{\circ}C$ in air atmosphere. From XRD, it is found that these results are due to the existence of NiO on film surface formed by annealing. As a results of them, TCR can be controlled by variation of sputter process parameter and annealing of thin film.

• 한국분말재료학회지
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• 제22권3호
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• pp.181-186
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• 2015

In this study, the effect of the friction stir welding (FSW) was compared with that of the gas tungsten arc welding (GTAW) on the microstructure and microhardness of Cu-Ni alloy weldment. The weldment of 10 mm thickness was fabricated by FSW and GTAW, respectively. Both weldments were compared with each other by optical microstructure, microhardness test and grain size measurement. Results of this study suggest that the microhardness decreased from the base metal (BM) to the heat affected zone (HAZ) and increased at fusion zone (FZ) of GTAW and stir zone (SZ) of FSW. the minimum Hv value of both weldment was obtained at HAZ, respectively, which represents the softening zone, whereas Hv value of FSW weldment was little higher than that of GTAW weldment. These phenomena can be explained by the grain size difference between HAZs of each weldment. Grain size was increased at the HAZ during FSW and GTAW. Because FSW is a solid-state joining process obtaining the lower heat-input generated by rotating shoulder than heat generated in the arc of GTAW.

• 한국자기학회지
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• 제3권4호
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• pp.289-292
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• 1993

3-Gun 고주파 마그네트론 스퍼터링법에 의해 [Ni/Fe/Cu] 다층박막과 [Fe/Ni/Fe/Cu] 다층 박막을 제조하고 Ni/Fe 두께비에 따른 자기저항특성을 조사하였다. 열처리에 의한 효과를 고나찰하기 위하여 진공열처리를 행하였다. 두 종류의 다층박막에서 사잇층 Cu 두께에 따른 자기저항의 진동 현 상을 관찰할 수 있었다. Ni과 Cu의 계면에 삼입된 Fe 두께가 약 $3\;\AA$일때 자기저항이 극대값을 보 였으며, Fe 두께가 $1~2\;\AA$일때 자기저항은 이에 비해 크게 감소하지 않았으나, 포화자장은 현저 히 감소하는 것으로 나타났다. ${[Fe(1\;\AA)/Ni(18\;\AA)/Fe(1\;\AA)/Cu(23\;\AA)]}_{20}Fe(80\;\AA)/Si$ 시편의 경우, 100 Oe의 포화자장에서 6%의 자기저항을 얻을 수 있었다. 열처리에 의해서는 자기저항이나 큰 변화를 관찰할 수 없었으며, 합금상 형성 여부는 확인할 수 없었다.