Modeling Electrophoretic Deposition on Porous Non-Conducting Substrates using Design of Experiments

Statistical design of experiments was used to model electroph-oretic deposition of yittria-stabilized zirconia (YSZ) particles on porous, non-conducting NiO–YSZ substrates. A 23–full-facto-rial matrix with three repetitions of the centerpoint was aug-mented with six axial runs and two additional centerpoints to form an inscribed central composite design. Fixed ranges of substrate firing temperature (11001–13001C), deposition voltage (50–300 V), and deposition time (1–5 min) were used as the in-dependent design variables to model responses of YSZ deposi-tion thickness, area-specific interfacial resistance (ASR), and power density. Regression equations were determined, which were used to optimize deposition parameters based on the de-sired responses of low interfacial polarization resistance and high-power density. Low substrate firing temperature (11001C) combined with a low voltage (50 V) and minimal deposition time (1 min) resulted in a 6 lm-thick YSZ film, a power density of 628 mW/cm2, and an ASR of 0.21 X. cm2. Increasing the substrate firing temperature, voltage, and time to 11741C, 215 V, and 3 minutes, respectively, reduced the ASR to 0.19X. cm2, increased YSZ film thickness to 25 lm, but had only a negligible effect on power density (600 mW/cm2). I