Hybrid piezochromic coatings for impact detection on composite substrates for aeronautic

Abstract

Structural Health Monitoring (SHM) is a major issue in the aeronautic field, especially for impact detection on composite materials which can be time consuming. Impact-sensitive coatings are an interesting way to save costs and time associated with these monitoring operations. This paper describes the successful preparation of a reversible piezochromic coating for impacts detection on composite substrates. It results from the incorporation of piezochromic pigments into a hybrid organic-inorganic matrix. It has been optimized by studying and quantifying their piezochromic behavior by UV-visible spectroscopy. It revealed that the piezochromic properties of the sensitive coating and the pigments alone are quite different and ruled by the hardness of the film. The obtained sensitivity and threshold pressure are determined to be 28% GPa−1 and 0.2 GPa respectively.