• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.120-122
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• 1994

We examined the magnetic properties as a function of annealing temperature of the as-quenched $Fe_{87}Zr_{7}B_{5}Ag_{1}$ amorphous alloy. The values of $H_{c}$=30m0e, $B_{a}$=0.44T and ${\mu}$i=146000 at $300^{\circ}C$ annealing treatment are obtained. The excel lent soft magnetic properties seem to result from the annihilation of quenching-Induced internal stress by the heat treatment and the change of microstructure due to the different relaxation behavior owing to adding insoluble element such as Ag. Therefore, the $Fe_{87}Zr_{7}B_{5}Ag_{1}$ amorphous alloy is quite promising for practical use as a core material in various transformers of high transformers of high frequency.

• 한국재료학회지
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• 제15권11호
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• pp.697-704
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• 2005

The deformation behavior of a bulk amorphous and crystallized amorphous $Zr_{22.5}Ti_{14}Cu_{12.5}Ni_{10}Be_{22.5}$ alloy extracted from a commercial golf club head was characterized at room temperature ana $300^{\circ}C$. At room temperature, amorphous specimens revealed higher yield stress and ductility than partially crystallized alloy specimens. Amorphous alloy displayed some plasticity before fracture, which resulted from strain hardening and repeated crack initiation and propagation. The fracture is mainly localized on one major shear band, and the compressive fracture angle of the amorphous specimen between the stress axis and the fracture plane was about $40^{\circ}$ Scanning electron microscope observations revealed mainly a vein-like structure in the amorphous alloy But the fracture surface of partially crystallized amorphous alloy consisted of vein-like and featureless fracture structure. The partially crystallized alloy extracted from the thick part of the club fractured in the elastic region, at a much lower stress level than the amorphous, suggesting that relatively coarse crystal particles formed during cooling cause the brittle fracture.

• 한국자기학회지
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• 제1권2호
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• pp.60-68
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• 1991

급속냉각기술로 제조된 $Nd_{14}Fe_{76}Co_{4}B_{6}$ 및 $Nd_{10.5}Fe_{79}Co_{2}Zr_{15}B_{7}$ 자성분말을 사용하여 성형체와 본드자석을 제조하였다. 자기특성, 최적충진률 등의 분말입도 및 형상비에 따른 거동은 합금조성에 따라 달리 나타난다. Co/Fe 비가 작은 저밀도의 $Nd_{10.5}Fe_{79}Co_{2}Zr_{1.5}B_{7}$ 합금이 같은 성형압력에서 성형체의 성형밀도 및 최적충진률이 높아 자기특성이 우수하였으나 반면에 분말입도에 따라 자기특성이 변화하였다. 성형밀도(p)와 성형압력(P) 사이 에는 ${\phi}(g/cm^{2})=5.2~5.6{\times}P^{0.045~0.065}(ton/cm^{2})$의 관계식이 성립된다. 높은 Nd/Fe 비를 갖는 급속냉각된 $Nd_{14}Fe_{76}Co_{4}B_{6}$ 합금의 초미세립(50~60 nm)으로써 높은 보자력($iH_{c}=14~15kOe$)을 보유하나, Nd/Fe비가 낮은 $Nd_{10.5}Fe_{79}Co_{2}Zr_{1.5}B_{7}$ 합금은 결정립이 조대하고(150~400 nm)Nd-rich한 입경계상의 발달이 부진하여 자벽고착기구가 주 보자력 기구 로 판명된 두 합금에서 고착지점으로서의 역할이 불충분하여 보자력이 낮은 것으로 판명되었다.

• 한국전기전자재료학회논문지
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• 제19권9호
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• pp.808-812
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• 2006

In this dissertation, Ru-Zr metal gate electrode deposited on two kinds of dielectric were formed for MOS capacitor. Sample co-sputtering method was used as a alloy deposition method. Various atomic composition was achieved when metal film was deposited by controlling sputtering power. To study the characteristics of metal gate electrode, C-V(capacitance-voltage) and I-V(current-voltage) measurements were performed. Work function and equivalent oxide thickness were extracted from C-V curves by using NCSU(North Carolina State University) quantum model. After the annealing at various temperature, thermal/chemical stability was verified by measuring the variation of effective oxide thickness and work function. This dissertation verified that Ru-Zr gate electrodes deposited on $SiO_{2}\;and\;ZrO_{2}$ have compatible work functions for NMOS at the specified atomic composition and this metal alloys are thermally stable. Ru-Zr metal gate electrode deposited on $SiO_{2}\;and\;ZrO_{2}$ exhibit low sheet resistance and this values were varied with temperature. Metal alloy deposited on two kinds of dielectric proposed in this dissertation will be used in company with high-k dielectric replacing polysilicon and will lead improvement of CMOS properties.

• 한국분말재료학회지
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• 제18권4호
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• pp.359-364
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• 2011

Zr-Ti alloy powders were successfully synthesized by magnesium thermal reduction of metal chlorides. The evaporated and mixed gasses of $ZrCl_4+TiCl_4$ were injected to liquid magnesium and the chloride components were reduced by magnesium leading to the formation of $MgCl_2$. The released Zr and Ti atoms were then condensed to particle forms inside the mixture of liquid magnesium and magnesium chloride, which could be dissolved fully in post process by 1~5% HCl solution at room temperature. By the fraction-control of individually injected $ZrCl_4$ and $TiCl_4$ gasses, the final compositions of produced alloy powders were changed in the ranges of Zr-0 wt.%~20 wt.%Ti and their purity and particle size were about 99.4% and the level of several micrometers, respectively.

• 한국주조공학회지
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• 제34권2호
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• pp.60-66
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• 2014

A Zr-based amorphous alloy specimen was produced by vacuum die casting process. The salt spray test was carried out using the specimens in the as-cast, $Al_2O_3$ and $ZrO_2$ particle blasted state. Using these specimens, the SEM-EDX and XRD analyses, DSC measurement and bending strength test were conducted. After the salt spray test, the specimens were not experienced phase change and thermal characteristics of the alloys were remained unchanged. In the as-cast specimen, corrosion products were not observed. However, in the $Al_2O_3$ particle blasted specimen, pitting corrosion occurred and the detected corrosion products were $ZrCl_2$ and $NaZrO_3$. Due to the salt spray test, bending strength of the $Al_2O_3$ blasted specimens showed about 100 MPa lower strength than the other specimens. The bending fracture surface was vein pattern which was shown typically in the amorphous alloys.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.519-520
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• 2007

In order to develop non-heated STAl(super thermal resistant Aluminum alloy) for ampacity gain conductor, the systematic research was carried out. Especially, the effect of a very small amount of Zr element in EC grade Al ingot on mechanical and electrical properties was our priority. As a result, it was found that the strength and recrystallization temperature of designed alloy was gradually increased with Zr addition up to 0.3wt.%. However, the electric conductivity showed no drastic change. The tensile strength and recrystalliztion temperature, $17.75\;kgf/mm^2$ and $420^{\circ}C$, was obtained at 0.3 wt.% Zr addition, respectively.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2801-2808
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• 2022

The synergistic effect of ZrC nanoparticle pining and Re solution in W matrix on the thermal stability of tungsten was studied by investigating the evolution of the microstructure, hardness and tensile properties after annealing in a temperature range of 1000-1700 ℃. The results of metallography, electron backscatter diffraction pattern and Vickers micro-hardness indicate that the rolled W-1wt%Re-0.5 wt% ZrC alloy has a higher recrystallization temperature (1600 ℃-1700 ℃) than that of the rolled pure W (1200 ℃), W-0.5 wt%ZrC (1300 ℃), W-0.5 wt%HfC (1400-1500 ℃) and W-K-3wt%Re alloy fabricated by the same technology. The molecular dynamics simulation results indicated that solution Re atoms in W matrix can slow down the self-diffusion of W atoms and form dragging effect to delay the growth of W grain, moreover, the diffusion coefficient decrease with increasing Re content. In addition, the ZrC nanoparticles can pin the grain boundaries and dislocations effectively, preventing the recrystallization. Therefore, synergistic effect of solid solution Re element and dispersed ZrC nanoparticles significantly increase recrystallization temperature.

• 한국재료학회지
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• 제11권5호
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• pp.405-412
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• 2001

본 연구에서는 $360^{\circ}C$ 물 및 $360^{\circ}C$, 70ppm LiOH 수용액 분위기의 static autoclave를 이용하여 새롭게 개발한 Zr 신합금 (Zr-0.4Nb-0.8Sn-xFeCrMn, Zr-0.2Nb-1.1Sn-xFeCrMn, Zr-1.0Nb-xFeCu) 의 부식 특성을 평가하였다. 합금의 미세구조를 광학현미경과 TEM을 이용하여 관찰하였고, 부식시험 중에 생성된 산화막은 SEM과 XRD를 이용하여 단면 및 결정구조를 조사하였다. 부식시험 결과, 3종의 합금 모두 $360^{\circ}C$ 물 분위기보다 $360^{\circ}C$, 70ppm LiOH 수용액 분위기에서의 부식저항성이 감소하였으며 특히, High Nb 합금의 경우 급격한 가속 부식현상을 나타내었다. 합금원소 첨가량과 관련하여 Nb의 함량을 고용도 이내로 줄이고 Sn을 적절히 첨가한 조성의 합금이 Sn을 첨가하지 않고 고용도 이상의 Nb을 가진 합금보다 우수한 부식저항성을 나타내었다. 또한 최종열처리가 부식에 미치는 영향의 경우에, 완전재결정 조직의 합금이 부분재결정 조직을 가진 합금보다 부식저항성이 감소되었는데 이는 기지조직에서 석출하늘 제 2상의 크기 및 분포에 의한 영향으로 사료된다.

• 한국재료학회지
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• 제12권8호
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• pp.624-633
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• 2002

In order to improve the hydrogen storage capacity and the activation properties of the hydrogen storage alloys, the rare-earth metal alloy series, MmN $i_{4.5}$M $n_{0.5}$Z $r_{x}$(x=0, 0.025, 0.05, 0.1), are prepared by adding excess Zr in MmN $i_{4.5}$M $n_{0.5}$ alloy. The various parts in hydrogen storage vessel consisted of copper pipes reached the setting temperature within 4~5 minutes after heat addition, which indicated that storage vessel had a good heat conductivity required in application. The performance test on storage vessel filled with rare-earth metal alloys of 1000 gr was also conducted after hydrogen charging for 10 min at $18^{\circ}C$ under 10 atm. It showed that the average capacity of discharged hydrogen volume was found to be for $MmNi_{4.5}$ $Mn_{0.5}$ and $MmNi_{4.5}$ $Mn_{x}$ 0.5/$Zr_{samples}$ indicated that the released amount of hydrogen for this $AB_{5}$ type alloys was more than 92 % of theoretic value, and also it was found that the optimum discharging temperature for obtaining an appropriate pressure of 3 atm was determined to be $V^{\circ}C$ for $MmNi_{4.5}$ $Mn_{0.5}$$Zr_{x}$(x=0, 0.025, 0.05, 0.1) hydrogen storage alloys. The released amount of these hydrogen storage samples was 125 $\ell$ , 122.4 $\ell$ and 108.15 $\ell$/kg for $MmNi_{4.5}$ $Mn_{0.5}$ $Zr_{0.025}$ $MmNi_{4.5}$M $n_{0.5}$Z $r_{0.05}$, and MmN $i_{4.5}$ Mn_0.5$Zr_{0}$, at $70^{\circ}C$ respectively. Amount of the 2nd phases increase with increase on Zr contents in $MmNi_{4.5}$$Mn_{0.5}$ $Zr_{ 0.1}$/ alloy. This phenomenon indicates that$ ZrNi_3$ in $MmNi_{4.5}$ $Mn_{0.5}$ $Zr_{x}$ / phase, which shows the maximum storage capacity and the strong resistance to intrinsic degradation, is considered as a proper alloy for hydrogen storage. As the Zr contents increase, the activation time and the plateau pressure decreases and sloping of the plateau pressure increases.creases.eases.s.