Current Research in Ultrasonic Non-Destructive Evaluation of Materials Properties

Ultrasonics based nondestructive testing techniques have been effective not only for flaw detection and evaluation purposes in materials but also for the characterization of materials properties and microstructures. In this paper, some of the important non-destructive research&developmental works carried out at the authors' laboratory on the characterization of material properties (microstructures and mechanical properties) in a variety of structural materials such as AISI type 316 austenitic stainless steels (SS), modified alloy D9 and Zircaloy-2 are discussed. Potential use of high frequency (>20MHz) ultrasonic measurements for characterisation of precipitation in AISI type 316LN SS that has a bearing on the properties and performance of the materials in service will be highlighted. Application of very high frequency (?1GHz) through scanning acoustic microscopy for various surface and sub-surface imaging of sensitized microstructures will be discussed.