The Relationship between Welding Conditions and Ultrasonic Reflection Coefficients of Dissimilar Metals Friction Welded Joints

이종재 막찰용접 이음부에서의 초음파 반사계수와 용접조건과의 관계

오세규,김동조,한상덕

부산수산대학 박용기계공학과,부산개방대학 기계공학과,한국중공업

Keywords: Friction Welding, Pulse-Echo Method, Coefficient of Reflection, Frictional Heating Time, Upsetting Pressure, T

Abstract

Friction welding has emerged as a reliable process for high-production commercial applications with significant economic and technical advantages. But nondestructive test in friction weld was not clearly developed. Therefore the experimental verification is necessary in order to understand the characteristcs of the pulse echo effects according to various change in welding conditions. This paper presents an attempt to determine the relationship between the varios welding conditions and the coefficients of reflection using the ultrasonic pulse echo method in dissibilar metals friction weld. The new approach of calculating the coefficients of reflection based on measured amplitudes of the echoes is applied in this paper. These coefficients provides a single quantitative measurement which involves both acoustic energy reflected at the welded interface as well as transmitted across the interface. As a result, it was known that the quantitave relationship between welding conditions and the coefficients of reflection using the ultrasonic pulse echo exists in dissimilar metals friction weld.