Papers by Author: Hyoun Kon Ku

Abstract: Electrophoretic deposition (EPD) technique was applied to deposit carbon nanotubes on a carbon fabric. Optimization of EPD conditions was investigated to improve electrical conductivity for CNTs/carbon fiber hybrid multiscale composites by Taguchi method. Based on design of experiment, a L9(3)4 orthogonal array was chosen to conduct experiments. Due to the electrical conductivity of composites increased with the increasing content of CNTs in composites, it was selected as the response on the analysis of the means (ANOM) and the signal to noise (S/N) ratio. In addition, scanning electron microscopy (SEM) was utilized to examine the distribution of CNTs on the surface of a carbon fabric. The statistical software MINITAB 14 was utilized to determine the optimal deposition conditions.

Abstract: This research makes comparisons of empirical fatigue-lives between AC8A Al alloy and the metal matrix composites (Al/Al2O3, Al/Al2O3/Al2O3p), and also includes comparisons of fatigue-lives between empirical fatigue-lives and estimated fatigue-lives from regular-periodic load testing, acoustic emission (AE) method to predict fatigue-crack initiation before visible in sight and SEM (Scanning Electron Microscope) photographs of each material. According to the test results of the notched specimen, the fatigue life of the hybrid metal matrix composites and the metal matrix composites, which are more brittle than the base matrix was shorter than that of the base matrix under both types of loads. In addition, the fatigue-life estimated from the damage summation method and that from experiments at random loads were fairly identical.