• International Journal of Precision Engineering and Manufacturing
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• v.2 no.4
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• pp.69-74
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• 2001

Powder forging technology has been introduced to manufacture the parts for vehicles. This paper describes the process conditions for the powder forging of aluminium also piston for vehicles including the determination of composition of aluminum alloy by experiment, preform design by FEM simulation, coed compaction of aluminum alloy powder, sintering of preform, and the experiment of powder forging. The mechanical properties such as hardness, tensile strength, and elongation of the farmed piston were invested and compared with casted piston and forged piston. The tensile strength and hardness of the piston formed by powder forging technology were much more excellent than other pistons.

• Particle and aerosol research
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• v.5 no.4
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• pp.153-158
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• 2009

Tungsten carbide powder was fabricated with carbothermal reaction by pulsed electric current flowing in compact of tunsten oxide and carbon. The mixed powder of tunsten oxide and carbon was ball-milled into ultrafine powders. The mixed powder of tungsten oxide and carbon was put into carbon mold and heat-treated at $1050{\sim}1200^{\circ}C$ by pulsed electric current flowing. The formation of tungsten carbide powder could be achieved by heat treatment at $1200^{\circ}C$ for 10 minitues.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.287-288
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• 2006

Two approaches for the fabrication of tailored powder composites with specially distributed pore-grain structure and chemical composition are investigated. Electrophoretic Deposition (EPD) followed by microwave sintering is employed to obtain functionally graded materials (FGM) by in-situ controlling the deposition bath suspension composition. $Al_2O_3/ZrO_2$ and zeolite FGM are successfully synthesized using this technique. In order to fabricate an aligned porous structure, unidirectional freezing followed by freeze drying and sintering is employed. By controlling the temperature gradient during freezing of powder slurry, a unidirectional ice-ceramic structure is obtained. The frozen specimen is then subjected to freeze drying to sublimate the ice. The obtained capillary-porous ceramic specimen is consolidated by sintering. The sintering of the graded structure is modeled by the continuum theory of sintering.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.83-84
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• 2006

Due to the capability of net shaping for complex 3D geometry, powder injection molding (PIM) is widely used for automotive parts, electronics and medical industry. In this study, an ultrasonic dental scaler tip produced by machining process was redesigned for the PIM process. An injection mold was designed and manufactured to produce the dental scaler tip by the PIM process.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.11a
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• pp.62-62
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• 2002

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.63-64
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• 2004

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.65-65
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• 2004

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.11a
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• pp.22-23
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• 2004

• Journal of the East Asian Society of Dietary Life
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• v.16 no.2
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• pp.180-185
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• 2006

To develop a new instant pumpkin gruel food, this study investigated the dried powder and gruel quality characteristics depend on drying method. The pumpkin powder was dried by infrared and freeze drying, and then milled to 80 mesh, after which the manufactured gruel was mixed with glutinous rice by heating. The gruels prepared by dried pumpkin powder were compared with steamed and freeze dried powder as a control, the crude protein and total sugar contents were high in the infrared drying powder, but freeze drying kept more carotenoid content. Soluble solid of gruel was higher in the freeze dried powder, and steam treated powder showed increased L and b values. Sensory test was carried out to select proper drying methods with 5-point scale. The gruel with freeze dried powder gained the highest score in overall quality. These results suggest that freeze drying could be used for manufacturing high quality instant pumpkin gruel.

• Journal of the Korean Wood Science and Technology
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• v.44 no.6
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• pp.872-879
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• 2016

Demand of natural interior finishing material has been widely sprayed in nowadays because many weak people as children, pregnant women, and elder people are being struggled with sick house syndrome due to volatile organic compounds such as formaldehyde, toluene, benzene, etc. Our research group developed a no-added formaldehyde adhesive for wood-based panels from mainly rice powder and some additives in the previous study for abating sick house syndrome. Since the rice powder adhesive provides a good source of nutrients with microorganisms, it was suspected a susceptibility of the rice powder adhesive to fungal and sapstain attack. We evaluated anti-sapstain activity of the rice powder adhesives modified by adding wood preservatives. We modified the rice powder adhesive by adding three different types of anti-sapstain preservatives at three different concentrations to assess their anti-sapstin activity. The bonding strengths of the modified rice powder adhesives were still outstanding performance on all samples. Moreover, the plywood manufactured with the modified rice powder adhesive satisfied outdoor use requirement for ordinary plywood (KS F3101, Korean Standard). The results obtained showed that at least 3% of preservative should be added to the rice powder adhesive to obtain effective anti-sapstain activity.