Effect of <scp> BaTiO ₃ </scp> Size on Damping and Friction‐Induced Vibration Characteristics of Polymer Matrix Piezoelectric Damping Composites

ABSTRACT Water‐lubricated bearings (WLB) play a crucial role in preventing lubricant oil leakage and simplifying shaft system design. However, the lubricating water film has a significantly lower load‐bearing capacity than the oil film. Therefore, improving the friction‐induced vibration characteristics of WLB is crucial. In this study, we fabricated BaTiO 3 /carbon black/polyurethane ternary piezoelectric damping composites (PDC) reinforced with BaTiO 3 ceramic particles of various sizes. BaTiO 3 absorbs mechanical vibrations and converts them into electrical energy, and conductive carbon black utilizes the electrical energy to generate damping heat. This novel energy dissipation mechanism, the piezoelectric damping effect, effectively suppresses friction‐induced vibrations. The piezoelectric damping mechanism improved the damping properties of PDC. However, hard BaTiO 3 inevitably remained at the contact interface, leading to severe abrasive wear. Using computer image analysis techniques, we characterized the morphology of the BaTiO 3 particles. We systematically investigated the effects of different‐sized BaTiO 3 particles on tensile strength, damping factor, friction coefficient, frictional heat, wear micromorphology, and friction‐induced vibration characteristics of PDC. Notably, the PDC containing 200 nm BaTiO 3 demonstrated excellent damping performance. The BaTiO 3 particles underwent rolling friction on the wear surface, which reduced the friction force and wear. Furthermore, friction‐induced vibration responses were effectively suppressed. The findings of this study contribute to a deeper understanding of the frictional response mechanisms influenced by different‐sized BaTiO 3 particles and provide experimental insights into the development of polymer matrix WLB composites with enhanced wear resistance and vibration‐damping capabilities.