• Proceedings of the KWS Conference
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.791-797
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• 2002

This paper introduces the partial melting process for solder application and characterization of its feasibility using Sn-Ag, and Sn-Cu solder alloys. ill order to show that the liquid phase in the semi-liquid state maintains the similar wettability as single-phase liquid, the wetting balance tests are conducted with varying temperatures and compositions. Also, as a new soldering technology, the microstructural and mechanical test were investigated. The results from this research indicate that the partial melting can yield satisfactory sider joints as long as the liquid phase acquires sufficient chemical activity. At a condition where the partial melting is effective, a direct correlation between the wettability and the surface tension is found to exist.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 한국에너지공학회 1998년도 추계 학술발표회 논문집
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• pp.126-133
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• 1998

• Journal of the Microelectronics and Packaging Society
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• 제7권2호
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• pp.63-68
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• 2000

This paper introduces the partial melting process for solder application and characterization of its possibility using off-eutectic Pb-Sn alloy. In order to show that the liquid phase in the semi-liquid state maintains the wettability as the single-phase liquid, the wetting balance test are conducted with varying temperatures and compositions. The results are then compared with the surface tension of liquid, both measured and calculated, to examine the correlation. The results from this investigation indicate that the partial melting can yield satisfactory solder joints as long as the liquid phase acquires sufficient chemical activity. At a condition where the partial melting is effective, a direct correlation between the wettability and the surface tension is found to exist. All alloys are found to show a reasonable wettability in semi-liquid state.

• Transactions of Materials Processing
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• 제20권2호
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• pp.118-123
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• 2011

Manufacturing of the bipolar plate of a direct methanol fuel cell (DMFC) by direct laser melting technology (DLM) was attempted. The DLM technology is highly influenced by process parameters such as laser power, scan rate and layering height. Therefore, an analysis of the DLM technology was performed under various conditions. The bipolar plates were fabricated using the DLM process with 316L stainless steel (STS 316L) plates and powder. Powder melting trials at various energy density were performed in order to select a feasible melting range for a given laser power. The melting line height increases and eventually saturates when the energy density increases, but decreases when the laser power increases at a given energy density. For the estimation of the potential performance of the bipolar plate, the surface roughness and contact resistance of the DLM layer were also analyzed. The changes of line height and thickness are useful information to report when manufacturing bipolar plate of fuel cell through the DLM process.

• Journal of Pharmaceutical Investigation
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• 제37권1호
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• pp.1-5
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• 2007

Solid dispersions of piroxicam were prepared by melting method using poloxamer as a carrier. The results of DSC and XRD studies showed that the amorphous farm of piroxicam coexisted with the crystalline form in the solid dispersions. However, the ratio of crystalline form of piroxicam in the solid dispersion prepared by melting method decreased in comparison with the same ratio of the solid dispersion prepared by solvent method. As the ratio of poloxamer in the solid dispersion increased, the ratio of the amorphous form of piroxicam in the solid dispersion increased. The dissolution rate of piroxicam from the solid dispersions was significantly higher than that from piroxicam powder. In comparison to the solid dispersion prepared by solvent method, the dissolution rate of piroxicam from the solid dispersion prepared by melting method was higher. As the ratio of poloxamer in the solid dispersion prepared by melting method increased, the initial dissolution rate decreased, however, the total amount dissolved at the end of the study increased.

• Composites Research
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• 제23권3호
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• pp.43-49
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• 2010

Basaltic fiber was prepared by continuous spinning process from Jeju Pyosun raw basalt materials. First, for confirming the melting characterization of basalt, basalt raw material put into Pt crucible and melted up to $1550^{\circ}C$ then quenched by dropping it into water. After quenching, the optimum fiber spinning conditions were investigated by measurement and analysis of XRD, TMA, high temperature viscosity, high temperature conductivity and high temperature microscope. The optimum spinning temperature and viscosity for preparation of continuous filament fiber were $1264^{\circ}C$ and $10^{2.8}$ poise at $1264^{\circ}C$, respectively. Properties of prepared spinning fiber were confirmed by tensile strength, FE-SEM, heat resisting test and others. The tensile strength of fiber prepared by spinning conditions of the bushing temperature $1240^{\circ}C$ and winder speed 4600rpm was 3660MPa.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제36권10호
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• pp.1241-1248
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• 2012

The objective of this study is to evaluate the thermal damage characterization of a silicon wafer subjected to a CW laser beam. The variation in temperature and stress during laser beam irradiation has been predicted using a three-dimensional numerical model. The simulation results indicate that the specimen might crack when a 93-$W/cm^2$ laser beam is irradiated on the silicon wafer, and surface melting can occur when a 186-$W/cm^2$ laser beam is irradiated on the silicon wafer. In experiments, straight cracks in the [110] direction were observed for a laser irradiance exceeding 102 $W/cm^2$. Furthermore, surface melting was observed for a laser irradiance exceeding 140 $W/cm^2$. The irradiance for surface melting is less than that in the simulation results because multiple reflections and absorption of the laser beam might occur on the surface cracks, increasing the absorbance of the laser beam.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제17권3호
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• pp.108-112
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• 2007

Cubic Zirconia single crystals having changeable color with light source were grown by skull melting method. Strong absorption of yellow color region light by Co and Nd and the absorption in violet color region by Fe led the color change from blue-green to red-purple with the light source from fluorescent to incandescent lamp. Color of crystals varied not only by the dopants but yttria contents and the conditions far heat treatment.

• Applied Microscopy
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• 제50권
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• pp.12.1-12.11
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• 2020

Hot stage microscopy (HSM) is a thermal analysis technique that combines the best properties of thermal analysis and microscopy. HSM is rapidly gaining interest in pharmaceuticals as well as in other fields as a regular characterization technique. In pharmaceuticals HSM is used to support differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA) observations and to detect small changes in the sample that may be missed by DSC and TGA during a thermal experiment. Study of various physical and chemical properties such sample morphology, crystalline nature, polymorphism, desolvation, miscibility, melting, solid state transitions and incompatibility between various pharmaceutical compounds can be carried out using HSM. HSM is also widely used to screen cocrystals, excipients and polymers for solid dispersions. With the advancements in research methodologies, it is now possible to use HSM in conjunction with other characterization techniques such as Fourier transform infrared spectroscopy (FTIR), DSC, Raman spectroscopy, scanning electron microscopy (SEM) which may have additional benefits over traditional characterization techniques for rapid and comprehensive solid state characterization.

• 보존과학연구
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• 통권21호
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• pp.57-75
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• 2000

We performed the scientific analysis through composition analysis, micro-structure investigation, melting point and hardness test to the glass beads excavated at Naesanri in Gosung. Through this investigation, we could examine closely the characterization of raw materials and manufacture technique As a result of micro-structure investigation of glass beads, it appeared that the bubbles in glass beads have remained. Coloring agents of yellow glass bead was remained to the shape of inclusion. And on observing the transparent solid particle, we can know that these do not melt the raw materials because of low melting temperature of a crucible. The result of composition analysis of all glass beads using ICP, these were classified as $Na_2O_2$-$SiO_2$ type of glass. Also, these added to $AI_2O_3$ to improve the durability. The value of Vickers hardness of glass beads appeared the HV 490-530. The HV 1,440 of the transparent solid particle was much more than that of inner glass bead. This means that raw materials do not melt because of a low melting temperature of a crucible. The result of melting temperature analysis of glass beads using DSC/TGA, it was measured about $1,250^{\circ}C$.