Characterization of microscopic residual stresses: A review

Residual stresses are important factors affecting the performance and lifespan of components, among which the influence of micro-residual stress on crack propagation and fatigue property is no less than that of macro-residual stress, so it cannot be underestimated in materials design, forming and processing, life prediction as well as failure analysis. However, the accurate characterization of micro-residual stress is still facing many challenges, and the interaction between micro-residual stress and microstructures has yet been clearly understood. In view of this, the latest progress in the characterization methods such as electron backscattered diffraction, focused ion beam-digital image correlation, nanoindentation, among others, in mapping the micro-residual stress is summarized, including the testing principle, scope of application, measurement accuracy, along with the corresponding limitations. In addition, the trends for techniques in probing micro-residual stress are also proposed with the aim of extending extra vision for further improving the measurement accuracy and systematic research on residual stresses on microscopic scale.