Papers by Author: Sung Jei Hong

Abstract: Nowadays, rapidly growing mobile machines such as tablet PC and smart phone equipped with touch screen panel using a sturdy material for products surface protection. Therefore, surge of chemical strengthening glass was increased. Through large areas of chemical strengthening glass, the surface scratch will cause a major failure. Most of these failures will be discarded because it is difficult to reuse. Thus, discarded chemical strengthening glass is expected to increase as with the demand. Accordingly, the importance of environmental pollution, waste landfill has been proposed. Recently, touch screen of chemical strengthened glass all-in-one type was commercialized. Therefore reuse is possible, due to surface of discarded chemical strengthening glass is washed and wipe off the electrode. In this study, we carried out the MLCA(Material Life Cycle Assessment; MLCA) on a chemical strengthening glass by landfill scenario, reuse scenario and identified the key issues.

Abstract: In this study the effects of harder ultrafine Al2O3 particles on the mechanical milling of ductile Cu flakes (200mesh, 70μm) have been investigated. The small hard Al2O3 particle in the mixture acted as an effective milling agent not only by inducing a drastic change of the Cu morphology from flattened flakes to equiaxed crystals but also by reducing the milling time required for a uniform dispersion of Al2O3 in the Cu matrix. This was more pronounced as the Al2O3 concentration increased. A critical concentration of the reinforcing Al2O3 required for a shape change was observed at the range of 8 to 9wt. %. All the hard Al2O3 particles were uniformly embedded in the ductile Cu matrix regardless of the concentration of Al2O3. By increasing the milling time, the weldment and fragmentation of the Cu flakes became significant and a uniformly distributed equiaxed composite structure (13wt.% Al2O3) was obtained at above 70 min..

Abstract: Highly dense Y2O3 ceramics have been fabricated by a magnetic pulsed compaction (MPC) which is capable of reaching a sufficiently high pressure (~1GPa) in a very short duration (a few microseconds), and a subsequent pressureless sintering at 1600°C. The Y2O3 green bodies with a relative density of about 68% were achieved by the application of the MPC process due to the effect of an enhanced rearrangement and a high speed movement of the particles, without the help of ceramic binder. Those compacts showed densities greater than 95%, which is very close to the theoretical density, after the subsequent pressureless sintering process at 1600 oC. The shrinkage rates of the diameter for the samples compacted by the MPC process were markedly reduced, when compared to those for the ones by the conventional compaction (CC) process.