• 한국세라믹학회지
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• 제16권4호
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• pp.225-236
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• 1979

The effect of $Ti^{+4}$ addition on the sinterability, microstructure, and temperature dependence of electromechanical coupling factor of magnetostrictive Ni-Cu-Co ferrite was investigated. The density of Ni-Cu-Co ferrite slightly increased by 2.0 mole % addition of either $TiO_2$ or $Fe_2TiO_4$, but tended to decrease by more than 2.0 mole % addition of $TiO_2$ or $Fe_2TiO_4$. As the content of either $TiO_2$ or $Fe_2TiO_4$ increased, the magnetocrystalline anisotropy compensation temperature also increased. Microstructure studies showed the stable grains when Ni-Cu-Co ferrite was sintered above 1, 20$0^{\circ}C$.

• 한국주조공학회지
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• 제21권2호
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• pp.127-134
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• 2001

Misch metal (rare earth element, Ce, La, Nd, Pr) which has large influence on high-temperature stability and toughness was added to the Al-5%Ni-5%Mg alloy, and squeeze casting was used for Al-5%Ni-5%Mg-(Mm) alloys. The effect of applied pressure and misch metal additions on mechanical properties in Al-5%Ni-5%Mg alloy by direct squeeze casting has been investigated. The applied pressure were 0 MPa(gravity casting), 25, 50 and 75 MPa. Squeeze-cast Al-5%Ni-5%Mg-(Mm) alloys had better mechanical properties than those of non-pressurized cast alloys because of the increased cooling rate by the application of pressure during solidification. By the addition of misch metal in Al-5%Ni-5%Mg alloy, better combination of strength and elongation was obtained. The addition of 0.3%Mm in Al-5%Ni-5%Mg alloy improved the heat resistant property due to the formation of fine eutectic phases.

• Progress in Superconductivity
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• 제6권1호
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• pp.64-68
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• 2004

We fabricated cube-textured Ni and Ni-W alloy substrates for coated conductors and characterized the effects of W addition on microstructure, mechanical strength, and magnetic properties of the substrate. Pure Ni and Ni-(2, 3, 5at.%)W alloys were prepared by plasma arc melting, heavily cold rolled and then annealed at various temperatures of $600-1300^{\circ}C$. The texture was evaluated by pole-figure and orientation distribution function (ODF) analysis. Mechanical properties were investigated by micro Vickers hardness and tension test. Ferromagnetism of the substrate was measured by physical property measurement system (PPMS). It was observed that Ni-W substrates had sharp cube texture, and the full-width at half-maximums (FWHMs) of in-plane texture was $^{\circ}$-5.57$4.42^{\circ}$, which is better than that of pure Ni substrate. In addition cube texture of Ni-W substrates was retained at higher temperature up to $1300^{\circ}C$. Microstructural observation showed that the Ni-W substrates had fine grain size and higher mechanical properties than the pure Ni substrate. These improvements are probably due to strengthening mechanisms such as solid solution hardening and/or grain size strengthening. PPMS analysis showed that addition of W effectively reduced saturation magnetization in applied magnetic field and Curie temperature.

• 대한금속재료학회지
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• 제48권3호
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• pp.194-202
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• 2010

Application of a stronger and more durable material for reactor pressure vessels (RPVs) might be an effective way to insure the integrity and increase the efficiency of nuclear power plants. A series of research projects to apply the SA508 Gr.4 steel in ASME code to RPVs are in progress because of its excellent strength and durability compared to commercial RPV steel (SA508 Gr.3 steel). In this study, the microstructural characteristics and mechanical properties of SA508 Gr.3 Mn-Mo-Ni low alloy steel and SA508 Gr.4N Ni-Mo-Cr low alloy steel were investigated. The differences in the stable phases between these two low alloy steels were evaluated by means of a thermodynamic calculation using ThermoCalc. They were then compared to microstructural features and correlated with mechanical properties. Mn-Mo-Ni low alloy steel shows the upper bainite structure that has coarse cementite in the lath boundaries. However, Ni-Mo-Cr low alloy steel shows the mixture of lower bainite and tempered martensite structure that homogeneously precipitates the small carbides such as $M_{23}C_6$ and $M_7C_3$ due to an increase of hardenability and Cr addition. In the mechanical properties, Ni-Mo-Cr low alloy steel has higher strength and toughness than Mn-Mo-Ni low alloy steel. Ni and Cr additions increase the strength by solid solution hardening. In addition, microstructural changes from upper bainite to tempered martensite improve the strength of the low alloy steel by grain refining effect, and the changes in the precipitation behavior by Cr addition improve the ductile-brittle transition behavior along with a toughening effect of Ni addition.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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• pp.201-201
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• 2003

It has been well known that Ni-MILC TFTs are acceptable for operation of LCD devices but still decrease of annealing temperature is desirable for the future devices like LCD on the plastic substrate. In this work, Cu was added to Ni-MILC in an attempt to lower the annealing temperature and enhance the MILC rate. It has been found that even small amount of Cu addition enhances the MlLC rate considerably. Also well One MILC can be distinguished from island type, which cannot be observed in pure Ni-MILC. Poly TFTs were fabricated with Cu/Ni-MILC and the effects of copper addition on the electrical properties were carefully investigated.

• Tribology and Lubricants
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• 제11권5호
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• pp.55-58
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• 1995

The effects of Ni contents in Cu base sintered friction material were studied. The contents of Ni were increased up to 9 wt% in the Cu-Sn matrix. The microstincture and tribological behavior of the friction material were examined. Pin on disk type of constant speed friction test rig were used to measure the friction and the wear rates. The results show that Ni addition increased the friction coefficients and decreased the wear rates of the materials. Relations between microhardness of the matrix and friction properties have been discussed. In addition optimum Ni content is recommended through the analysis of wear debris.

• 한국표면공학회지
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• 제16권2호
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• pp.41-47
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• 1983

An investigation has been performed on the effects of temperature and Ni addition on the wetting behaviour of Cu on W substrate in hydrogen atmosphere. An sessile drop method was used to measure a wetting angle. The concentration profiles of W, Cu and Ni elements in W/Cu - 5 Ni specimen were made by EPMA. With increasing temperature, the wetting angle of Cu droplet on W plate decreases and the time to reach an equilibrium wetting angle is shortened in hydrogen atmosphere. The addition of Ni improves appreciably the wettability of Cu on W. With increasing Ni content in Cu liquid droplet(0, 1, 3, 5%), the wetting angle is decreased from 21$^{\circ}$to 0$^{\circ}$.

• 한국수소및신에너지학회논문집
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• 제8권3호
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• pp.137-141
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• 1997

The effects of Ag addition to Zr-based hydrogen storage alloys ($Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$, $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.3}Cr_{0.1}$ and $Zr_{0.6}Ti_{0.4}V_{0.4}Ni_{1.2}Mn_{0.3}Fe_{0.1}$) on the electrode properties were examined. Ag-free and Ag-added Ze-based alloys were prepared by arc melting, crushed mechanically, and subjected to the electrochemical measurement. In $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$ alloy, 0.08 wt% Ag addition to the alloy improved the activation rate. Also Ag addition improved both activation property and discharge capacity in $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.3}Cr_{0.1}$. For these Ag-added alloys, discharge capacities with the change of charge-discharge current density(10mA, 15mA and 30mA) are almost constant. Showing very high rate capability, discharge capacity of $Zr_{0.6}Ti_{0.4}V_{0.4}Ni_{1.2}Mn_{0.3}Fe_{0.1}$ alloy increased by Ag addition to the alloy. When the amount of Ag addition in $Zr_{0.7}Ti_{0.3}V_{0.4}Ni_{1.2}Mn_{0.4}$ alloy increased too much, the electrode properties became worse. Unveiling mechanism of effect of Ag addition is now progressing in our laboratory.

• 한국주조공학회지
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• 제8권4호
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• pp.459-466
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• 1988

This study was carried out in the austempering temperature and time after Ni, Mo addition in purpose of modification of impact toughness of austempered ductile irons. Addition of alloy element and austempering treatment of $900^{\circ}C$ 60 minutes followed by $300^{\circ}C$, $350^{\circ}C$ and $400^{\circ}C$ for 60 minutes, in this case impact value was increased by ideal mixed structure. But impact value was decreased when holing time is 120minutes, this is attributed to segregation and carbide precipitation from high carbon austenite. Highest impact value was obtained by $350^{\circ}C$ (Mo-addition) and $400^{\circ}C$ (Ni-addition). This phenomena was caused by presence of remained austenite. At all austempering temperature,, Ni-added specimen showed higher impact values than that of Mo-added specimen. And hardness property was affected by austempering temperature and holding time rather than amounts of alloying element.

• 한국산업융합학회 논문집
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• 제24권4_2호
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• pp.435-441
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• 2021

This research was performed to study the effect of the Ni + Mo addition on the fatigue properties in 12Cr steel. After heat treatment of 12Cr steel and 12Cr-Ni-Mo steel, tensile tests, impact tests, hardness tests, and rotary bending fatigue tests were performed, respectively. The fatigue fracture surface was observed and analyzed using SEM and EDS. The fatigue limit of 12Cr steel was 554 MPa, which was 49 MPa higher than 505 MPa of 12Cr-Ni-Mo steel. Striations, which are the shape of the typical fatigue fracture surface, were observed at the fracture surface near the starting point of fatigue fracture in the 12Cr steel and 12Cr-Ni-Mo steel. However, unlike the case of 12Cr steel, 12Cr-Ni-Mo steel also had a mixed fracture surface with the fatigue and the ductile fracture surface. When brittle non-metallic inclusions exist near the starting point of fatigue failure, the crack propagation was further promoted and the fatigue life was drastically reduced.