Self-sensing metallic material based on piezoelectric particles

Structural parts’ integrity should remain as specified and designed, although it can change due to ageing and use by environmental action and accidental events. Structural parts design is carried out considering certain service conditions that can be different from operating conditions. These parts often experience dynamic solicitations that change in amplitude and frequency over time, which may cause the part’s failure. The part’s real condition can be assessed by Structural Health Monitoring systems, which grant significant social, economic, and environmental impact, as they can reduce maintenance costs and ensure the integrity of the part and its surroundings. This can be performed with an integrated monitoring system comprising sensors, on the surface or embedded, into the components. However, surface sensors are subject to damage, from collisions and/or environmental action, and embedding sensors can be very challenging and may result in a weakened part. A Self-Sensing Material (SSM) was developed based on piezoelectric particles embedded in metal parts by a solid-state processing technology. The material can act as a sensor and continuously monitor its condition. The SSM's generates an electrical voltage signal when subject to strain stimulus. Moreover, the solid-state processing technology employed promotes mechanical properties enhancement in the processed zone, not only by the grain size reduction but also due to the incorporation of the piezoelectric particles. The response to a set of dynamic loads was assessed and was found to be coherent with the solicitations applied.