Using SEM techniques for failure analysis of critical aeroengine components

Abstract

Aeroengine components operate under particularly severe conditions, including the combination of both high mechanical stresses and elevated temperatures in chemically aggressive environments. These normal operational requirements will eventually promote both cyclic and time dependent failure mechanisms related with creep-fatigue damages. Therefore, the use of adequate preventive inspection techniques is mandatory in order to maximize safety and reliability levels of these components during service. However, there are some occasional and unpredictable material failures which must be conveniently investigated in order to avoid future hazardous situations. Scanning electron microscopy (SEM) can play a major role in the context of evaluation of failed components, allowing the observation of fracture surfaces and other material's features which are essential to the identification of some particular failure mechanisms.