Evaluation of material microstructure changes in high speed tool steel by the non-collinear wave mixing technique with MST(magnetostrictive transducer)

Abstract

Evaluation of material microstructure changes plays an important role in predicting material failure. Both destructive and nondestructive testings can be used to evaluate the variation of material microstructure. Destructive methods are used to directly verify the changes of material via microstructure picture in a vigorous manner while nonlinear ultrasonic NDE can render a promising tool for the cases. In this study, the MST driven non-collinear wave mixing technique is implemented to evaluate the material microstructure changes in high speed tool steel. The resonant wave is used to analyze the acoustic nonlinearity which is influenced by microstructure changes with various austenitizing temperature effects. Correlation microstructure change between the acoustic nonlinearity and material microstructure is accomplished to explore the feasibility of the non-collinear mixing technique.