CHARACTERIZATION OF SILICON CARBIDE MICROSTRUCTURE USING NONDESTRUCTIVE ULTRASOUND TECHNIQUES

摘要

Ultrasonic nondestructive evaluation has conventionally been used to measure elastic properties and locate large flaws in many types of materials used for a number of different applications. Recent advances in acoustic spectroscopy have enabled ultrasound techniques that can be used to examine the microstructure of dense ceramic bodies. In this study, methodology is developed for nondestructively characterizing the microstructure of spark plasma sintered (SPS) silicon carbide using high frequency ultrasound acoustic spectroscopy. Several silicon carbide samples with varying microstructures were produced by varying the processing and sintering conditions. Comparison of the acoustic attenuation spectra of the silicon carbide samples with microstructural information from field emission scanning electron microscopy (FESEM) is used to determine a relationship between microstructural properties and ultrasound response.