The Application Study Of Surface Acoustic Waves On Detecting Material Processing Surface Damages

Laser-generated surface acoustic wave technology is one of the new research directions of the non-destructive testing field,and it plays important roles in the modern industrial development.This paper proposes a research approach for detecting the surface Young's modulus of the silicon samples based on the dispersion properties of surface acoustic waves,and it aims at providing a precise non-destructive method for detecting the mechanical properties of materials.The paper mainly contains three parts,which includes the generation mechanism and detecting technology of the surface acoustic wave signals,the dispersion theory of laser generated surface acoustic waves,the surface damage experimental measurement of materials by laser generated SAWs.As for the generation mechanism and detecting technology of the SAW signals: To begin with,the paper discusses two generation mechanisms which are about the thermo elastic generation and the abrasive generation,then the parsing theory model related about the generation of SAWs is established from the actual application perspective.Additionally,the paper also introduces two different surface acoustic wave measuring technologies from the non-contact and contact perspectives.As for the dispersion theory of laser generated surface acoustic waves: the paper established the layered model about the machining surface damage of materials from the aspects of parsing dispersion properties.At the same time,the theoretical dispersion curves are got by MATLAB programs based on this model.As for the surface damage experimental measurement of materials by SAWs: The surface damage of silicon samples is detected by the SAW experimental devices.Firstly,the SAWs time-domain signals are got by the experiments.Secondly,the corresponding frequency-domain signals of the detected materials are got after the process of FFT,then the experimental dispersion curves can be calculated by the phase-spectrum method.Last but not least,the Young's modulus of the detecting samples can be acquired by the matching process of dispersion curves.To verify the correctness of the detecting results,the contrast experiments are operated using the Nano-indenters.Through the above researches,it can be concluded that the method of detecting the materials' surface damage by SAWs is reliable and precise,and it provides a wide approach for the surface damage detecting technologies.