Real‐Time Visualisation of the Portevin–Le Chatelier Effect With Mechanoluminescent‐Sensing Film

Abstract: The use of the mechanoluminescence (ML) technique to directly observe the Portevin–Le Chatelier (PLC) effect is described. A uniaxial tensile test of an aluminium alloy plate coated with SrAl 2 O 4 : Eu 2+ (SAOE) ML‐sensing film was performed, and a high‐speed camera recorded ML images simultaneously. Strong ML light in response to the PLC bands was emitted from the coated SAOE ML‐sensing film and could be seen clearly with the naked eye. The position, the slope angle of the band front and propagation velocity of the PLC bands were measured directly from the ML images. Momentary interplay between two face‐to‐face propagating PLC bands was observed and captured in the ML images. The results show that real‐time visualisation of the PLC effect was achieved using this ML technique.