Method for Measuring the Acoustic Emission of Developing Microcracks in Machine Parts

Abstract

A method for measuring the acoustic emission of developing microcracks in machine parts has been developed. The performed analysis of the obtained dependences of the pulses number and their amplitude-frequency characteristics on the magnitude of the mechanical stress allows us to identify the very initial stages of the microdefects development: sliding along the grain boundaries, their destruction, movement of dislocation clusters, the formation and development of microcracks. At the extreme horizontal sections of elastic deformation, the ratio of the effective lengths of microcracks for a spring with a mileage of 30 thousand km and a spring with a zero mileage is 1.3. The localization of the microdefect in the studied sample of an extended form on average does not exceed 0.5%.