Lead zirconate-titanate (PZT) thick films of perovskite structure Pb(Zr x Ti 1-x )O 3 were fabricated on the curved surface of IN738 nickel-based supper alloy substrate up to 15 mm thickness using sol-gel deposition technique without polyvinylpyrrolidone. The films were heated at 200 C with 10 wt% excess PbO, pyrolyzed at 400 C, and subsequently annealed at 650 C, 700 C, and 800 C. Au and Pt thin films were deposited as bottom and top electrodes, respectively. PZT films of different thicknesses and thermal treatment conditions were characterized to investigate the effect of process on crystalline phase development, orientation, and microstructure morphology. Thereby, formation of fairly smooth, semi-dense, and crack-free random orientated thick films as well as an increase in the average grain size and stress relaxation was observed as the film thickness increased. Having optimized the coating process, intrinsic and extrinsic dielectric, ferroelectric and piezoelectric properties were measured as a function of the film thickness, orientation, grain size, and domain wall motions to evaluate the remnant polarization (P r ¼ 7.6-17.5 mC/cm 2 ), coercive field (E c ¼ 2.5-4 kV/ cm), permittivity (" r ¼ 276-326), dielectric loss (tan(%) ¼ 2.7-3), and piezoelectric charge coefficient (d 33 ¼ 71-145 pm/ V) of the PZT thick films prepared potentially to be used as high bandwidth 1-5 MHz structural health monitoring transducers.

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In this work the effect of wire electrical discharge machining parameters such as current, pulse offtime, open circuit voltage and gap voltage on the surface roughness and volumetric material removal rate of a 2601 cold worked tool steel was studied using a modified Taguchi orthogonal array (L-16M). After the design, the experiments were performed employing a five axis wire electrodischarge machine, and the average feed rate was measured during the work. Values of the surface roughness were measured by means of a portable device. Using the results of experiments and analysis of variance (ANOVA), importance and effectiveness of each parameter was discerned. By means of analysis of signal to noise ratio, optimised combination of the machining parameters was determined.