• Proceedings of the Korean Society of Laser Processing Conference
• /
• 1999.11a
• /
• pp.56-59
• /
• 1999

• Transactions of Materials Processing
• /
• v.33 no.1
• /
• pp.55-72
• /
• 2024

• Transactions of Materials Processing
• /
• v.33 no.2
• /
• pp.132-150
• /
• 2024

• Transactions of Materials Processing
• /
• v.33 no.3
• /
• pp.214-230
• /
• 2024

• Tribology and Lubricants
• /
• v.34 no.6
• /
• pp.209-216
• /
• 2018

Sapphire is a substrate material that is widely used in optical and electronic devices. However, the processing of sapphire into a substrate takes a long time owing to its high hardness and chemical inertness. In order to process the sapphire ingot into a substrate, ingot growth, multiwire sawing, lapping, and polishing are required. The lap grinding process using pellets is known as one of the ways to improve the efficiency of sapphire substrate processing. The lap grinding process ensures high processing efficiency while utilizing two-body abrasion, unlike the lapping process which utilizes three-body abrasion by particles. However, the lap grinding process has a high material removal rate (MRR), while its weakness is in obtaining the required surface roughness for the final polishing process. In this study, we examine the effects of free abrasives in lap grinding on the material removal characteristics of sapphire substrate. Before conducting the lap grinding experiments, it was confirmed that the addition of free abrasives changed the friction force through the pin-on-disk wear test. The MRR and roughness reduction rate are experimentally studied to verify the effects of free abrasive concentration on deionized water. The addition of free abrasives (colloidal silica) in the lap grinding process can improve surface roughness by three-body abrasion along with two-body abrasion by diamond grits.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.2
• /
• pp.464-468
• /
• 2012

Three solvent systems, chlorobenzene (ink 1), chlorobenzene/o-dichlorobenzene (ink 2) and chlorobenzene/tetrahydronaphthalene (ink 3), were compared as printable inks for the fabrication of polymer light-emitting diodes (PLEDs) using poly[2-methoxy-5-(2-ethylhexyl-oxyl)-1,4-phenylenevinylene (MEH-PPV) as an emissive material and an inkjet printer (Fujifilm Dimatix DMP-2831). Ink 1 clogged the printer's nozzle and gave non-uniform film. Inks 2 and 3 were used to fabricate PLEDs with ITO/PEDOT:PSS/MEH-PPV/LiF/Al configurations. The best performance (turn-on voltage, 3.5 V; luminance efficiency, 0.17 cd/A; luminance, 1,800 cd/m) was obtained when ink 3 was used to form the emissive layer (thickness, 49 nm), attributable to the better morphology and suitable thickness of the MEH-PPV layer.

• Journal of the Korean Society of Industry Convergence
• /
• v.16 no.3
• /
• pp.95-102
• /
• 2013

It is indispensable to modern society metal processing since the industrialized rapidly, but it is a metalworking cutting fluid immediately. In addition, this means selecting a emulsion on the basis of quality criteria processing method, the material of the material, cutting depth, cutting speed, Djourou fence Liang, and surface roughness, cutting oil, the shape of the device based on the emulsion, I will be the structure of the tank, filtration equipment also changes. In particular, acting bacteria is now breeding in response to the passage of time due to metal ion degradation due to heat generated hydraulic fluid leakage, humidity tung, during processing, seep from processing material at the time of processing the water-soluble cutting oil for generating the malodor by dropping significantly the performance of the cutting oil to corruption from, sometimes by introducing various additives to suppress spoilage in advance. In this study, we expect the effect of the cost reduction in the extension of fluid replacement cycle through the application of the management apparatus and deep understanding in the management of cutting fluid, the working environment through the understanding and interest of workers in the production site more than anything I try to become useful for the improvement.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.27 no.4
• /
• pp.212-219
• /
• 2017

To become a person that is suitable to the 'High-Touch' generation where emotion takes over, we can focus on 6 skill including design, story, harmony, empathy, play, and meaning. Among these skills, harmony with design was chosen as the most important skill. Design can be seen as the basic element of all business, but it will be difficult to match the flow of the future Sensibility and intuitive generation with just the modern design that has been made based on reasonable and objective information and knowledge. This study suggests system and standardization of Sensibility surface processing design that satisfies great quality, attractive quality and Sensibility quality by applying surface processing design of product and Sensibility cognitive factors felt by the consumer by setting differentiated strategy and CMF (Color, Material, Finishing) understanding along with the importance of design materials in primary aspect. By considering the efficacy/characteristic of new surface processing characteristic/differentiation/possibility of implementation according to setting direction of differentiated CMF strategy per type of parts applied to the product, visual surface processing sample was implemented. Through this, it is expected that practical communication connected tool and Sensibility surface processing design's strategic access framework can be applied by understanding and sharing comprehensive elements such as target product, part type, applied material, applied surface processing, surface color, surface texture, and implementing feeling to environments such as designers, CMF designers, surface processing experts, and engineers in IT, electronics, and other areas. when developing a product.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2004.10a
• /
• pp.733-736
• /
• 2004

Actual trends in automotive industry lead to an increase use of lightweight structures imposing the need for high strength aluminum alloys with complex shape. In the electromagnetic stirring process, it has many merits which are the exact control ability about material processing and a good point of the protection of environment comparison with the mechanical stirring. The interface of cells consisting of primary particle formed by the electromagnetic stirring due to particle regrowth during cooling the alloy. By electromagnetic stirring process, the microstructure of material has a good point, also it can control the material processing exactly.

• Transactions of Materials Processing
• /
• v.11 no.8
• /
• pp.701-709
• /
• 2002

Aluminium foam material is highly porous material, which has the complicated cellular structure defined by randomly distributed pores in metallic matrix. This structure gives the characteristic properties which cannot be achieved by any other conventional processes. As the properties of aluminium foam material significantly depend on its porosity, a desired profile of properties can be tailored by changing the foam density. But various defects lead to undesirable effects on the mechanical properties. Mechanical properties are dependent on cell sizes and aspect ratios. Therefore, this paper presents the effects of various processing parameters of various parameters on the mechanical properties. For the sake of this, combined stirring was used to fabricate aluminum foam materials by the parameters. Compression and bending tests were performed to investigate the effects of cell sizes and aspect ratios on the mechanical properties.