Papers by Author: S.Y. Luo

Abstract: This paper investigates the effect of the CBN abrasive types, sizes, concentration, bond amount, and porosity of a vitrified-bonded CBN wheel on grinding ratio, grinding forces, and surface roughness of grinding hardened steels. The experiment results showed that during grinding hardened steels the amount of bond with increase of the depth of cut increased, which makes the wheel to have a better bonding strength to get a better grinding ratio and surface roughness of the workpiece. The grinding forces produced increased with the increase of the depth of cut. In addition, too much porosity of a vitrified CBN wheel will cause the low bond strength, leading the wheel to wear rapidly. Hence, to obtain a higher grinding ratio and better surface roughness of the workpiece during the grinding hardened steels should select relatively a higher amount of bond, a lower porosity, and a higher grit strength and concentration, but the grinding forces produced were relative higher.

Abstract: The paper was to investigate the development of the graphite/phenolic resin composite materials that were fabricated by compression molding for the bipolar plate of the fuel cell. Effect of the different amounts of resin and the graphite powder size on the porosity, density, bending strength, and electrical resistance of the composites would be analyzed. In addition, the composites of the bipolar plates would be machined into the groove channel using high speed milling, which then assembles into single fuel cell. The I-V performance of the single fuel cell would be also discussed. The experimental results showed that when the larger amount of resin was employed, the resulting composites had a lower porosity, a larger electrical resistance, and a higher bending strength. The graphite/resin composites showed a good machinability during the high-speed milling. Finally, the graphite/resin composites of bipolar plates containing 25-30 vol. % phenolic resins were fabricated into a single fuel cell, which displays a relatively better I-V performance.