Transportation industries, such as aerospace and automotive demand high efficiency using lightweight parts. Carbon Fiber Reinforced Plastics (CFRP) present promising materials for transportation industry parts due to their lightweight and highstrength properties. Forming and machining processes are required to manufacture parts from carbon fiber composite materials. The near-net shaping process forms the parts, and the final accurate shape and hole are accomplished using the machining process. However, high-strength carbon fiber chips and dust from the machining process cause cutting tool wear and low productivity. The hybrid CRD (Cutting, Routing and Drilling)/water-jet machine improves tool life and productivity because its water-jet process, employed before the mechanical machining process cuts roughly without chips and dust. In this study, the hybrid CRD/water-jet machine we developed was introduced and its machining performance was evaluated using a drilling process. The delamination factor and surface roughness of drilled holes were compared with the results from a conventional machine tool.

Defects in the insulator bushing are the major caution of destroying a switchgear. An epoxy bushing is composed of epoxy-molded insulator layer and a conductor. That means, a porosity or delamination defect could be included in the insulating layer by the manufacturing process. An inspection method is required to secure integrity of the bushing. An ultrasonic-immersion system has the power to produce a required effect to examine critically an epoxy material with high degree of fineness. In this research, an optimized ultrasonic immersion system was developed and applied to examine critically the epoxy-layer of bushings. As results of the result of a careful examination, both artificial defects and delamination were detected by the system. Currently, the ultrasonic-immersion system should be applied for examining the epoxy-layer of the bushing carefully.