• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.4
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• pp.336-346
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• 1994

We studied the reaction between silicon and carbon. Silicon granules and silicon with 0.2 wt% carbon powders were prepared for sample and then they were heated up to the $1450^{\circ}C, 1550^{\circ}C, 1650^{\circ}C, 1700^{\circ}C$ and were dwelled 1 hr and 4 hrs, respectively. we studied the change of morphologies of molten silicon and the formation of SiC following the reaction withcarbon using optical microscope, SEM, and XRD. Above the melting point of silicon, oxygens are precipitated during the decomposition of quartz used crucible. SiO formed from the reaction between molten silicon and precipitated oxygen evaporated and made the surface defects. SiC were formed with the reaction between the unreacted carbon and molten silicon. Polytype of the SiC formed at the solidification interface was ${\alpha}-SiC$.

• Journal of the Korean institute of surface engineering
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• v.20 no.4
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• pp.144-153
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• 1987

In the case of dipping the Ni-Resist cast iron into molten aluminum with iron content, the thickness of intermetallic compound was remarkably increased with increasing iron content. The thickness was shown by following equation in the range of 1-3% iron content; $x=22.5t^{1/2}+4.47{\cdot}t{\cdot}(Fe%)$. where, x is thickness(${\mu}m$), t the time (minute), Fe% the iron w/o. When the Ni-Resist cast iron was dipped into the molten aluminum containing zinc content, the intermetallic compound thickness was also increased with increasing zinc contents. And thickness was represented by the following equation in the range of 2-10% zinc content; $x=3.46t^{1/2}+0.27{\cdot}t{\cdot}(Zn%)$. However, in the case of dipping the Ni-resist cast iron into molten aluminum with silicon content, the thickness of intermetallic compound was decreased with increasing silicon content, as shown in the following equation; $x=7.17t^{1/2}-0.15{\cdot}t{\cdot}(Si%)$. The intermetallic compound formed onto Ni-Resist cast iron was identified to be $FeAl_3\;and\;Fe_3Al$. As the result of hardness measurement, the peak hardness appeared in the intermetallic compound at near interface of the cast iron and the compound.

• Journal of Korea Foundry Society
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• v.25 no.4
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• pp.161-167
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• 2005

The experiment of hot dip interaction tests was carried out in order to study the formation behavior of interfacial reaction layer between as-received STD61 hot work tool steel and a commercial pure aluminum melt, Al-xwt.%Fe(x=0.2, 0.5, 0.8 and 1.1) alloys melt and Al-xwt.%Si(x=1.0, 4.0, 7.0 and 10.0) alloys melt, respectively. The results show that the reaction layer, over 300 ${\mu}m$ in thickness, is easily formed by the dissolution of silicon from as-received tool steel. When the iron content in the aluminum alloy is higher than 1.1 wt.%, the thickness of reaction layer decreases below 180 ${\mu}m$ by preventing iron dissolution from the tool steel. The silicon dissolved from tool steel acts as a strong promoter on the formation of reaction layer, but the alloyed silicon in molten aluminum alloys acts as an inhibitor on the formation of reaction layer.

• Journal of Electrochemical Science and Technology
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• v.11 no.4
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• pp.392-398
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• 2020

Producing solar grade silicon using an inexpensive method is a key factor in lowering silicon solar cell costs; the direct electrochemical reduction of SiO₂ in molten salt is one of the more promising candidates for manufacturing this silicon. In this study, SiO₂ granules were electrochemically reduced in molten CaCl₂ (850℃) using Ag-Si eutectic droplets that catalyze electrochemical reduction and purify the Si product. When Ag is used as the working electrode, the Ag-Si eutectic mixture is formed naturally during SiO₂ reduction. However, since the Ag-Si eutectic droplets are liquid at 850℃, they are easily lost during the reduction process. To minimize the loss of liquid Ag-Si eutectic droplets, a cylindrical graphite container working electrode was introduced and Ag was added separately to the working electrode along with the SiO₂ granules. The graphite container working electrode successfully prevented the loss of the Ag-Si eutectic droplets during reduction. As a result, the Ag-Si eutectic droplets acted as stable catalysts for the electrochemical reduction of SiO₂, thereby producing one-dimensional Si rods through a mechanism similar to that of vapor-liquid-solid growth.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.3 no.2
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• pp.117-124
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• 1993

It was found that the basic principle of continuous crystal growth method was following as; the powder supplied from the feeding system is molten in the graphite crucible under the ambient gas. After forming the molten zone in the lower part of the crucible, the seed crystal is deeped into the melt and pulled down with the rotation so that the melt crystallized from the seed. When the lowering rate, rotation rate, feeding rate and temperature are correct, the single crystal can grow. The critical melt level, the feeding rate, the growth rate, the change of the shape of molten zone by the graphite susceptor and crucible, the position of work coil, the balance between the gravitational force of melt and the centrifugal force originated from the rotation of seed which are the variables of the crystal growth and the sintering phenomenon of melt surface were researched.

• Korean Journal of Metals and Materials
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• v.47 no.7
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• pp.423-432
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• 2009

In the galvanizing coating process, the effects of the silicon content on the coatability and wettability of molten zinc were investigated on Dual-Phase High Strength Steels (DP-HSS) with various Si contents using the galvanizing simulator and dynamic reactive wetting systems. DP-HSS showed good coatability and a well-developed inhibition layer in the range of Si content below 0.5 wt%. Good coatability was the results of the mixed oxide $Mn_{2}SiO_{4}$, being formed by the selective oxidation on the surface, with a low contact angle in molten zinc and a large fraction of oxide free surface that provided a sufficient site for the molten zinc to wet and react with the substrate. On the other hand, with more than 0.5 wt%, DP-HSS exhibited poor coatability and an irregularly developed inhibition layer. The poor coatability was due to the poor wettability that resulted from the development of network-type layers of amorphous ${SiO}_{2}$, leading to a high contact angle in molten zinc, on the surface.

• Applied Microscopy
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• v.8 no.1
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• pp.77-79
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• 1978

Al-Si junctions were made by vacuum deposition of aluminium on to silicon wafers and examined by TEM. The uneven interfaces of the junctions are formed due to the surface tension of the molten solution resulting in preferential dissolution of silicon in aluminium at some areas. These undesirable uneven interfaces affect the junction shape and so the over-all characteristics of the devices.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1996.06a
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• pp.325-350
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• 1996

• Journal of Welding and Joining
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• v.32 no.3
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• pp.68-73
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• 2014

Among through silicon via (TSV) technologies, for replacing Cu filling method, the method of molten solder filling has been proposed to reduce filling cost and filling time. However, because Sn alloy which has a high coefficient of thermal expansion (CTE) than Cu, CTE mismatch between Si and molten solder induced higher thermal stress than Cu filling method. This thermal stress can deteriorate reliability of TSV by forming defects like void, crack and so on. Therefore, we fabricated SiC composite filling material which had a low CTE for reducing thermal stress in TSV. To add SiC nano particles to molten solder, ball-typed SiC clusters, which were formed with Sn powders and SiC nano particles by ball mill process, put into molten Sn and then, nano particle-dispersed SiC composite filling material was produced. In the case of 1 wt.% of SiC particle, the CTE showed a lowest value which was a $14.8ppm/^{\circ}C$ and this value was lower than CTE of Cu. Up to 1 wt.% of SiC particle, Young's modulus increased as wt.% of SiC particle increased. And also, we observed cross-sectioned TSV which was filled with 1 wt.% of SiC particle and we confirmed a possibility of SiC composite material as a TSV filling material.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.1
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• pp.37-43
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• 1995

The proper choice of the solvent is a prerequisite for solution growth of silicon. In the present work, the temperature to dissolve at least 1 atomic% silicon was calculated in various molten solvents.