• Korean Journal of Materials Research
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• v.5 no.4
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• pp.412-419
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• 1995

과공정 Al-18wt%Si합금의 초정 Si입자의 미세화에 미치는 첨가원소의 영향에 관하여 조사하였다. 초정 Si입자의 크기는 P량이 증가함에 따라 미세해졌으며 적정 P량은 40ppm이었다. 최적주입온도는 AlCuP, CuP 경우 각각 75$0^{\circ}C$, 80$0^{\circ}C$이었으며 미세화 처리 후 10분 이상 경과되어도 초정 Si입자의 크기는 변화가 없었다. 또한 WDS분석 결과 초정 Si내에 AIP가 핵생성 site로 존재함을 알 수 있었다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1993.04a
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• pp.54-58
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• 1993

Cu, Si, Mg, Ca, Cd, Sn, Pb등이 첨가되는 Al계 bearing 합금은 베어링 특성이 우수하여 최근 자동차드의 엔진 부품용 베어링소재로 많이 사용되어지고 있다. 합금원소 Si는 합금의 경도를 향상시키며 Si-rich한 경한 입자를 생성시켜 소착저항력(antiseizure)을 향상시키며 또한 합금의 주조성도 향상시켜 내마모성이 요구되는 Al계 베어링 합금에 주합금원소로 첨가된다. 본 연구에서는 강제죠반법과 급냉응고법을 이용하여 Al-Pb-Gu계와 Al-Si-Gu-Pb계 베어링합금을 제조하였다. 베어링합금이 급냉응고법으로 제조되었기 때문에 합금의 기지에는 Cu가 과포된 상태로 존재하여 석출경화에 앞서 행하여지는 용체화처리와 같은 효과가 얻어졌다. 본 실험에서는 Cu가 과포화된 기지를 갖는 주조상태의 시료를 시효열처리하여 석출경화된 베어링합금을 얻어서 석출경화에 의한 기지강화가 베어링합금의 내마모성질에 어떠한 효과를 가져오는지 규명하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.155-155
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• 2008

계속되는 반도체 산업의 발달로 반도체 배선 공정에서는 Al을 대체할 배선 금속으로 Cu에 대한 관심이 집중되고, 일부 공정에서는 Al을 대신하여 사용하고 있다. 이러한 Cu는 Al에 비교하여 많은 장점을 가지고 있지만 Si 기판과 저온에서 쉽게 확산되는 큰 문제점을 가지고 있다. 따라서 이러한 문제를 해결하기 위한 방법으로 현재까지 연구된 대안으로는 Cu와 Si기판 사이에 확산방지막을 삽입하는 것이 대안으로 알려져 있다. 본 연구는 Cu 금속배선 공정을 위하여 Cu와 Si기판과의 확산을 효과적으로 방지할 확산방지막을 텅스텐(W)을 주 구성 물질로 여기에 불순물을 첨가한 W-C-N 확산방지막에 대하여 연구하였으며, 특히 W-C-N 확산방지막의 결정 및 표면 구조에 대한 물성 특성을 연구하였다. 여러 조건변화에 따라서 확산방지막의 특성을 확인하기 위하여 조건이 다르게 증착된 W-C-N 확산방지막을 상온에서 고온으로 열처리하여 열처리 전후를 WET-SPM (Scanning Probe Microscope)을 사용하여 그 물리적 특성을 조사하였다. 이러한 분석을 통하여 가장 안정된 W-C-N 확산방지막의 증착조건을 확인하였으며, 이를 기반으로 박막의 물리적 특성을 연구하였다.

• Resources Recycling
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• v.23 no.1
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• pp.33-39
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• 2014

In this study, the solubility of Cu, which is a main metal component of wasted PCB, in $CaO-SiO_2-Al_2O_3-MgO$ slag system was investigated. Each 20 grams of Cu chips and the quaternary slag manufactured was placed in an carbon crucible and melted for 10 hours in the temperature between 1673 K and 1825 K to confirm the equilibrium state. The oxygen partial pressure was controlled by the ratio of CO and Ar gas in the range of $10^{-17.23}$ to $10^{-15.83}$ atm. The concentration of Cu in the slag increased with increasing oxygen partial pressure, slag basicity, and MgO content in the slag. The concentration of Cu in the slag decreased with increasing temperature. The Cu dissolution reaction in the slag is an exothermic reaction.

• Korean Journal of Materials Research
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• v.22 no.7
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• pp.329-334
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• 2012

Two types of nanoclusters, termed Cluster (1) and Cluster (2) here, both play an important role in the age-hardening behavior in Al-Mg-Si alloys. Small amounts of additions of Cu and Ag affect the formation of nanoclusters. Two exothermic peaks were clearly detected in differential scanning calorimetry(DSC) curves by means of peak separation by the Gaussian method in the base, Cu-added, Ag-added and Cu-Ag-added Al-Mg-Si alloys. The formation of nanoclusters in the initial stage of natural aging was suppressed in the Ag-added and Cu-Ag-added alloys, while the formation of nanoclusters was enhanced at an aging time longer than 259.2 ks(3 days) of natural aging with the addition Cu and Ag. The formation of nanoclusters while aging at $100^{\circ}C$ was accelerated in the Cu-added, Ag-added and Cu-Ag-added alloys due to the attractive interaction between the Cu and Ag atoms and the Mg atoms. The influence of additions of Cu and Ag on the clustering behavior during low-temperature aging was well characterized based on the interaction energies among solute atoms and on vacancies derived from the first-principle calculation of the full-potential Korrinaga-Kohn-Rostoker(FPKKR)-Green function method. The effects of low Cu and Ag additions on the formation of nanoclusters were also discussed based on the age-hardening phenomena.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.2
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• pp.37-42
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• 2000

The comparative study of texture of Al/Ti thin films deposited on low-dielectric polymer and $SiO_2$substrates has been investigated. Fifty-nm-thick Ti films and 500-nm-thick Al-1%Si-0.5%Cu (wt%) films were deposited sequentially onto low-k polymers and $SiO_2$by using a DC magnetron sputtering system. The texture of Al thin film was determined using X-ray diffraction (XRD) theta-2theta ($\theta$-2$\theta$) and rocking curve and the microstructure of Al/Ti films on low-k polymer and $SiO_2$substrates was characterized by cross-sectional transmission electron microscopy (TEM). Both the $\theta$-2$\theta$ method and rocking curve measurement suggest that Al/Ti thin films deposited on $SiO_2$have stronger texture than those deposited on low-k polymer. The texture of Al thin films strongly depended on that of Ti films. Cross-sectional TEM revealed that grains of Ti films on $SiO_2$substrates had grown perpendicular to the substrate, while the grains of Ti alms on SiLK substrates were formed randomly. The lower degree of (111) texture of Al thin films on low-k polymer was due to Ti underlayer.

• Journal of Magnetics
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• v.19 no.4
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• pp.327-332
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• 2014

The effect of minor element additions (Ca, Al) on microstructural change and magnetic properties of Fe-Nb-Cu-Si-B alloy has been investigated, in this paper. The Fe-Si-B-Nb-Cu(-Ca-Al) alloys were prepared by arc melting in argon gas atmosphere. The alloy ribbons were fabricated by melt-spinning, and heat-treated under a nitrogen atmosphere at $520-570^{\circ}C$ for 1 h. The soft magnetic properties of the ribbon core were analyzed using the AC B-H meter. A differential scanning calorimetry (DSC) was used to examine the crystallization behavior of the amorphous alloy ribbon. The microstructure was observed by X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM). The addition of Ca increased the electrical resistivity to reduce the eddy current loss. And the addition of Al decreased the intrinsic magnetocrystalline anisotropy $K_1$ resulting in the increased permeability. The reduction in the size of the ${\alpha}$-Fe precipitates was observed in the alloys containing of Ca and Al. Based on the results, it can be concluded that the additions of Ca and Al notably improved the soft magnetic properties such as permeability, coercivity and core loss in the Fe-Nb-Cu-Si-B base nanocrystalline alloys.

• Journal of Powder Materials
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• v.29 no.3
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• pp.233-239
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• 2022

Aluminum alloys are extensively employed in several industries, such as automobile, aerospace, and architecture, owing to their high specific strength and electrical and thermal conductivities. However, to meet the rising industrial demands, aluminum alloys must be designed with both excellent mechanical and thermal properties. Computer-aided alloy design is emerging as a technique for developing novel alloys to overcome these trade-off properties. Thus, the development of a new experimental method for designing alloys with high-throughput confirmation is gaining focus. A new approach that rapidly manufactures aluminum alloys with different compositions is required in the alloy design process. This study proposes a combined approach to rapidly investigate the relationship between the microstructure and properties of aluminum alloys using a direct energy deposition system with a dual-nozzle metal 3D printing process. Two types of aluminum alloy powders (Al-4.99Si-1.05Cu-0.47Mg and Al-7Mg) are employed for the 3D printing-based combined method. Nine types of Al-Si-Cu-Mg alloys are manufactured using the combined method, and the relationship between their microstructures and properties is examined.

• Korean Journal of Metals and Materials
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• v.49 no.8
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• pp.642-648
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• 2011

This paper describes an experimental study on ultrasonic welding of similar and dissimilar metals. There are optimum welding conditions which are found for welding of Al/Al and Al/Cu. It evaluated weldability using tensile test, SEM observation and EDX-ray analysis. Both ultrasonic welding of Al/Al and Al/Cu have amplitude as the variable factor. Al/Cu welding was examined again with welding time as variable factor to find the best conditions. The more welding time or amplitude increase, the better weldability. The optimum conditions for ultrasonic welding of Al/Al were formed at pressure 0.25 MPa, welding time 0.25 sec, amplitude 90%. Pressure 0.25 MPa, welding time 0.4 sec, amplitude 80% are optimized for Al/Cu ultrasonic metal welding and solid-state diffusion generated by ultrasonic vibration and frictional heat is confirmed at the welded interface.

• Corrosion Science and Technology
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• v.18 no.6
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• pp.300-311
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• 2019

The corrosion behaviors of twinning-induced plasticity (TWIP) steels with different alloying elements (Cu, Al, Si) in a neutral aqueous environment were investigated in terms of the characteristics of the corrosion products formed on the steel surface. The corrosion behavior was evaluated by measuring potentiodynamic polarization test and electrochemical impedance spectroscopy. For compositional analysis of the corrosion products formed on the steel surface, an electron probe x-ray micro analyzer was also utilized. This study showed that the addition of Cu to the steel contributed to the increase in corrosion resistance to a certain extent by the presence of metallic Cu in discontinuous form at the oxide/steel interface. Compared to the case of steel with Cu, the Al-bearing specimen exhibited much higher polarization resistance and lower corrosion current by the formation of a thin Al-enriched oxide layer. On the other hand, Si addition (3.0 wt%) to the steel led to an increase in grain size, which was twice as large as that of the other specimens, resulting in a deterioration of the corrosion resistance. This was closely associated with the localized corrosion attacks along the grain boundaries by the formation of a galvanic couple with a large cathode-small anode.