A study of the electrophoretic deposition of Bioglass® suspensions using the Taguchi experimental design approach

This paper presents a study of the Taguchi design method to optimise the rate of electrophoretic deposition (EPD) of Bioglass® particles from aqueous suspensions. The effect of Bioglass® concentration, pH and electric field was investigated. An orthogonal array of L16 type with mixed levels of the control factors was utilized. Multivariate analysis of variance (MANOVA) and regression analysis based on the partial least-square method were used to identify the significant factors affecting the deposition rate and its stability during constant-voltage EPD. It was found that the pH of the suspension significantly influences the deposition rate whereas the applied electric field has the smallest effect on the deposition rate. In addition, the interaction between the Bioglass® concentration and pH, which are key processing parameters influencing the deposition rate, was found to be significant. Although a high deposition rate was obtained at low electric field (5 V/cm) and pH 7, the instability of the suspension in particular at high Bioglass® concentrations resulted in an increase in the variability of the deposition rate. The optimal EPD condition predicted was verified by experiments and good qualitative agreement was obtained. The experimental results and statistical analyses are discussed based on the current knowledge of the EPD of ceramic materials.