61 / 2024-09-20 10:22:44

SrAl2O4-based mechanoluminescent coatings for visualization of friction force and cavitation erosion

erosion erosion,mechanoluminescent coating,real-time monitoring

Anti-erosion erosion and wear-resistant protective coatings applied to the surfaces of fluid machinery are widely used in high-tech industries such as aerospace and shipping. Without real-time monitoring methods, any failure of these protective coatings directly threatens the safe operation of equipment and components. This study designs a functional SrAl₂O₄:Eu²⁺, Dy³⁺ coating using atmospheric plasma spraying technology, which can emit light under external forces exceeding 81.2 MPa. For example, it can produce visible green light during cavitation erosion when bubbles implode or under friction during contact. Therefore, embedding this coating under the protective layer has the potential to predict failures. The research also found that the mechanoluminescent properties of the functional coating is easily affected by lattice defects, amorphous phases, and the oxidation states of europium ions. After vacuum thermal reduction treatment, this functional coating is more sensitive to friction, micro-jets, and shock waves, and can differentiate stress variations through light brightness. Later, after applying a polyurethane coating on its surface, when the polyurethane encounters cavitation erosion and its thickness is only about 0.1 mm, this functional coating will light up to signal that the polyurethane layer is about to fail. If the protective coating is repaired in time, the mechanoluminescent coating can be reused multiple times. Thus, this work provides a mechanoluminescent coating that can emit light under cavitation erosion or friction, offering a method for monitoring of when protective coatings might fail.