In-situ ultrasonic evaluation of structural/nuclear materials

Abstract

Physical properties of components through ultrasonic non-destructive evaluation play a vital role to understand in quality and strength materials and also help to extend life of the components. Measurements of ultrasonic velocity and attenuation as a function of temperature were used to reveal the structural/phase transitions, initiation and growth of fatigue-induced damages, and life-limiting fatigue crack during the aging of materials. Indigenously designed experimental set-ups was designed for in-situ ultrasonic velocities and attenuation measurement over a wide range of temperature from 120 to 300 K and 300 to 1200 K. The ultrasonic velocity/attenuation measurements carried out on AISI316 stainless steel, β-quenched zircaloy-2 specimen and maraging steel were used to explore the formation and resolution/recrystallization of intermetallic and coherent precipitations. Further, the ultrasonic velocity/attenuation measurements carried out in bulk and nano perovskites samples (La1xSrxMnO3, Nd1xSrxMnO3, Sm1xSrxMnO3 and Pr1xSrxMnO3) were used to explore the phase transition (TC), charge ordering (TCO), and Jahn-Teller (TJT) temperature. The bulk and nanocrystalline nature of the perovskites were explained based on observed anomalies at transition temperature. The plot of first derivative of temperature dependent ultrasonic parameters was used to reveal the precise information to detect the early stages of microstructural and substructure variations in material.