공중 초음파 탐상 기법을 적용한 항공기 브레이크 디스크의 내부결함 검출에 관한 연구

Abstract

The aircraft industry is an advanced, complex technological industry that has a strong impact on other industries and, for the nation as a whole, it is a strategically important industry for strengthening international competitiveness through technological superiority. developed countries throughout the world have been promoting the aircraft industry as an engine of continuous growth and development of advanced technology. the impotance of the industry is acute in areas of maintaing superior defense technology, promoting rapid-growth industries, and improving productivity. Cf-SiC an SiC/SiC composites have a high thermal conductivity, and excellent corrosion and wear resistance, low coefficient of thermal expansion and light welght using in the parts of the aerospace apply to aircraft thrust deflector, jet vane, combustion chamber, elevens, body flap, shingle. So, the state of the art new material of carbon fiber-reinforced silicon carbide when using both internal and external crack detection and composite materials that may occur during the manufacturing process of the composite material, using condition and the quantitative reliability to the physical behavior characteristic is determined by the non-desructive techniques and evaluated according to the external environment study on valuation techniques is essential. Typically, the ultrasonic testing performs the ultrasonic detection using the contact ultrasonic probe, howener, by using the NAUT technique, it is possible to conduct the non-contact ultrasonic testing without the couplant that delivers the ultrasonic since it is able to do the ultrasonic focusing in the air. Since the transmission and reception of the ultrasonic occurs on the steady state, the NAUT is able to conduct the ultrasonic detection on the materials in high temperature(200℃) or low temperature(10℃) which were not possible to perform with the existing contact detection at the room temperature, or specimens with rough surface, complex shape or small section. The Non-caontact Air-coupled Ultrasonic Testing(NAUT) used in this paper is the most advanced ultrasonic testing technique. it is a nondestructive testing that compliments the energy loss occurred due to the acoustic impedance difference in the air with two transmitting/receiving non-contact ultrasonic probe and enables the non-contact ultrasonic testing through high-powered ultrasonic focusing by using high-frequency band ultrasonic Pulser-Recelver. In this paper, we apply the most advanced techniques of non-contact air ultrasonic technique of ultrasonic techniques of non-destructive testing techniques to perform a study on internal defect detection indentification and assessment of carbon-fiber reinforced silicon carbide composites and to perform basic research and applied research.