Microstructural Characterisation of Nuclear Materials by Ultrasonics

Over last two decades, significant progress has been made on the characterisation of microstructures and material properties using ultrasonic attenuation and velocity measurement methods. Ultrasonic characterisation of microstructural feature in nuclear structural materials is a challenging and a very useful task to the industries. In this paper, some of the important developmental works carried out on characterisation of microstructures in a variety of nuclear structural materials such as AISI type 316 austenitic stainless steels, modified alloy D9, and Zircaloy-2 are presented. Potential of high frequency (>20 MHz) ultrasonic measurements for characterisation of precipitation that have a bearing in the properties and performance of the materials in service has also been highlighted. Paper also discusses the use of very high frequencies in the GHz range through scanning acoustic microscopy for the characterisation of sensitized microstructures in AISI type 304 LN stainless steel.