• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.76-76
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• 2003

• Journal of Powder Materials
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• v.14 no.2 s.61
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• pp.108-115
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• 2007

Cu-Ni-P alloy nano powders were fabricated by the electrical explosion of electroless Ni plated Cu wires. The effect of applied voltage on the explosion was examined by applying pulse voltage of 6 and 28 kV, The estimated overheating factor, K, were 1.3 for 6 kV and 2.2 for 28 kV. The powders produced with pulse voltage of 6 kV were composed of Cu-rich solid solution, Ni-rich solid solution, and $Ni_3P$ phase. While, those produced with 28 kV were complete Cu-Ni-P solid solution and small amount of $Ni_3P$ phase. The initial P content of 6.5 at.% was reduced to 2-3 at.% during explosion due to its high vapour pressure.

• Journal of Fisheries and Marine Sciences Education
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• v.10 no.1
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• pp.69-78
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• 1998

Thermal sprayed Cu-Ni alloy coating on the carbon steel was carried out impingement erosion-corrosion test and electrochemical corrosion test in the marine environment. The impingement erosion-corrosion behavior and electrochemical corrosion characteristics of substrate(SS400) and thermal sprayed Cu-Ni coating was investigated, and the corrosion control efficiency of Cu-Ni coating to substrate was estimated quantitatively. Main results obtained are as follows : 1) The weight loss rate of Cu-Ni coating layer by the impingement erosion-corrosion compared with substrate was smaller in high specific resistance solution than in low specific resistance solution. 2) The corrosion potential of Cu-Ni coating layer spray coating in the marine environment became more noble than that of substrate. 3) With the lapse of time, corrosion current density of Cu-Ni coating layer became stable, but that of substrate was increased. 4) As the corrosion control efficiency of Cu-Ni coating layer in the marine environment was over 90%, its anti-corrosion characteristics was excellent.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.1
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• pp.11-16
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• 2001

CuNi alloy films are deposited by co-sputtering of dual targets (Cu and Ni, respectively). Effects of the co-sputtering conditions, such as powers applied to the targets, deposition pressures, and substrate temperatures, on the structural and electrical properties of deposited films are systematically investigated. The composition ratio of Ni/Cu is almost linearly decreased by increasing the DC power applied to the Cu target from 25.6 W to 69.7 W with the RF power applied to the Ni target unchanged(140 W). it is noted that the chamber pressure during deposition and the film thickness give rise to a change of the Ni/Cu ratio within the films deposited. The former may be due to a higher sputtering yield of Cu atom and the latter due to the re-sputtering phenomenon of Cu atoms on the surface of deposited film. The film deposited at higher pressures or at lower substrate temperatures have a smaller crystallite size, a higher electrical resistivity, and much more voids. This may be attributed to a lower surface mobility of sputtered atoms over the substrate.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.272-276
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• 2001

Multicomponent $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ bulk matallic glass alloy shows good bulk glass forming ability due to its high resistance to crystallization in the undercooled liquid state.1) In this study, DSC and X-ray diffractometry have been performed to confirm the amorphous structure of the master $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy. To investigate the mechanical properties and deformation behaviors of the bulk metallic $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy, a series of compression tests has been carried out at the temperatures ranging from $351^{\circ}C$ to $461^{\circ}C$ and at the various initial strain rates from $2{\times}10^{-4}s^{-1}\;to\;2{\times}10^{-2}s^{-1}$. There are two types of nominal stress-strain curves. The one shows linear stress-strain relationship meaning fracture at maximum stress, the other shows plastic deformation including steady-state flow. Also DSC analysis for the compressed specimens has been performed to investigate the change of thermal stability and crystallization behavior for the various test conditions.

• Transactions of Materials Processing
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• v.10 no.7
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• pp.565-572
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• 2001

It is well known that a multicomponent $Zr_{4l.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ bulk metallic glass alloy shows good bulk glass forming ability due to its high resistance to crystallization in the undercooled liquid state. DSC and XRD have been performed to confirm the amorphous structure of the master alloy. To investigate the mechanical properties and deformation behavior of the bulk metallic $Zr_{4l.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy, a series of compression tests has been carried out at the temperatures ranging from $351^{\circ}C$ to $461^{\circ}C$at the various initial strain rates from $2{\times}10^4s^1$ to $2{\times}10^2s^1$. Three types of nominal stress-strain curves have been identified such as linear stress-strain relationship meaning fracture at maximum stress, plastic deformation including stress overshoot and steady-state flow, plastic deformation without stress overshoot depending on the strain rate and test temperature. Also DSC analysis for the compressed specimens was carried out to investigate the change of structure, thermal stability and crystallization behavior for the various test conditions.

• Transactions on Electrical and Electronic Materials
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• v.12 no.1
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• pp.20-23
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• 2011

Amorphous Ti-(50-x)Ni-xCu (at%) (x = 20, 25, 27, 30) alloy ribbons were prepared by melt spinning. Subsequently, the crystallization behavior of the alloy ribbons was investigated by X-ray diffraction and differential scanning calorimetry. ${\Delta}T$ (the temperature gap between $T_g$ and $T_x$) increased from 33 K to 47 K and the wavenumber ($Q_p$) decreased from 29.44 $nm^{-1}$ to 29.29 $nm^{-1}$ with increasing Cu content from 20 at% to 30 at%. The activation energy for crystallization decreased from 188.5 kJ/mol to 170.6 kJ/mol with increasing Cu content from 20 at% to 25 at%; afterwards, the activation energy remained near constant. Crystallization occurred in two-stage: amorphous-B2-$TiCu_2$ in Ti-Ni-Cu alloys with Cu content less than 25 at%, while it occurred in three-stage; amorphous-B2-TiCu-$TiCu_2$ in Ti-Ni-Cu alloys with Cu content more than 27 at%.

• Journal of the Korean Society for Heat Treatment
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• v.27 no.1
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• pp.1-9
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• 2014

For connector material applications, the influence alloying elements of Mn, Cr, Fe, and Ti and cold rolling reduction on the mechanical property, electrical conductivity and bendiability of Cu-Ni-Si-P alloy was investigated. The hot rolled plates were solution treated at $980^{\circ}C$ for 1.5 h, quenched into water, cold rolled by 10% and 30% reduction in thickness, and then aged at $440{\sim}500^{\circ}C$ for 3, 4, 5 times. respectively. Cu-Ni-Si-P-x alloys cold rolled by 10 reduction before heat treatment have a good bendability compare to cold rolled by 30 reduction. Cu-3.4Ni-0.8Si-0.03P-0.1Ti shows the peak strength value of 759 MPa, an electrical conductivity of 39%IACS, an elongation of 10% and a hardness of 256 Hv aged at $440^{\circ}C$ for 6 hrs. Thus it is suitable for lead frame and connector.

• Journal of the Korean Society for Heat Treatment
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• v.5 no.3
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• pp.149-156
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• 1992

Transformation behavior and reversible shape memory effct of Ti-Ni-Cu alloys with various Cu content has been investigated by means of electrical resistivity measurement, differential scanning calorimetry. X-ray diffraction and strain gage sensor. The transformation sequence in Ti-Ni-Cu alloys substituted by Cu for Ni up to 5at.% occurs to $B2{\leftrightarrow}B19^{\prime}$ and it proceeds in two stages by addition of 10 at.%Cu. i.e. $B2{\leftrightarrow}B19{\leftrightarrow}B19^{\prime}$. But the content of Cu increases up to 20at.%, it has been transformed in one stage ; $B2{\leftrightarrow}B19$. The shape change of Ti-40Ni-10Cu alloy which was constrain aged in circular form bended in $B2{\leftrightarrow}B19$ transformation but it spreaded out in $B19{\leftrightarrow}B19^{\prime}$ transformation. The amount of reversible shape change (${\Delta}{\varepsilon}$) of Ti-47Ni-3Cu alloy constrain aged at $400^{\circ}C$ after solution treatment has a maximum value of about $5.6{\times}10^{-3}$, but that of cold rolled and constrain aged specimens exhibits a little value independent of Cu concentrations.

• Korean Journal of Materials Research
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• v.26 no.1
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• pp.8-12
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• 2016

Effects of conventional rolling(CR) and differential speed rolling(DSR) on the microstructure and mechanical properties of Cu-Ni-Si alloy were investigated in detail. The copper alloy with thickness of 3 mm was rolled to 50 % reduction at ambient temperature without lubricant with a differential speed ratio of 2:1. The conventional rolling in which the rolling speed of upper and lower rolls is identical was performed under identical rolling conditions. The shear strain introduced by the CR showed positive values at positions of upper roll side and negative values at positions of lower roll side. However, it showed zero or positive values at all positions for the samples rolled by the DSR. The microstrucure and texture development of the as-rolled copper alloy did not show any significant difference between CR and DSR. The tensile strength of the DSR processed specimen was larger than that of the CR processed specimen. The effects of rolling methods on the microstructure and mechanical properties of the as-rolled copper alloy are discussed in terms of the shear strain.