Electrical properties of UV-irradiated thick film piezo-sensors on superalloy IN718 using photochemical metal organic deposition

Lead zirconate-titanate thick films of perovskite structure Pb(Zr_0.52Ti_0.48)O₃ were fabricated on the curved surface of IN718 superalloy substrate using photochemical metal organic deposition technique. The films were heated at 200 °C, irradiated by UV lamp (365 nm, 6 W) for 10 min, pyrolyzed at 400 °C, and subsequently annealed at 700 °C for 1 h after successive multi-step coating with 10 wt.% excess PbO. Fairly smooth, dense, and crack-free polycrystalline thick films of Au/PZT/Au structure were deposited on IN718. The films were characterized to investigate the effect of photochemical deposition process and substrate on the crystalline, morphological, dielectric, ferroelectric and piezoelectric properties. Remanent polarization (P_r = 20.2 μC/cm²), coercive field (E_c = − 10 kV/cm), permittivity (ε_r = 324@1 kHz), dielectric loss (tanδ ≈ 3%), and piezoelectric charge coefficient (d₃₃ = 113.4 pm/V) of the PZT thick film transducers were measured and interpreted as regards domain wall motions. Consequently, the photochemical grown lead zirconate-titanate thick film on the superalloy substrate IN718 was confirmed to be consistent to structural health monitoring due to its acceptable electrical response.