Optimization and Modeling of Oxidation Process Parameters of α-Brass Alloy

The objective of this work is to optimize the parameters (time and temperature) of the oxidation process and the alloy composition (alloy type) with addition of a small amount of oxide particles (0.2%TiO2, 0.2%Y2O3 and 0.2%Al2O3) separately to α-brass alloy. Taguchi optimization with L16 orthogonal array, signal to noise ratio(S/N) and analysis of variance (ANOVA) were applied on these four alloys. In this study, the weight gain per unit surface area (∆W/Ao) of the oxidized specimens for characterizing the oxidation extent was measured at different oxidation temperatures (500, 600, 700 and 800⁰C) and times (1, 10, 30 and 50) hrs for the base alloy and three modified alloys containing a small amount of oxide particles of 0.2%TiO2, 0.2%Y2O3 and 0.2%Al2O3, respectively. It was found that the weight gain/surface area (∆W/Ao) increases continuously with increasing time and temperature for the investigated alloys. It was obtained that the alloy containing 0.2% Al2O3 has the lowest rate of oxidation and reveals great enhancements in the oxidation resistance in comparison with the base alloy at all temperatures. It was found that the contribution percentage was 33.78% for oxidation time followed by oxidation temperature 30.9% and alloy type (modified brass) 19.94%. The results of the weight gain (∆W/Ao) measurement propose that the oxidation kinetic of the whole investigated brass alloys follows the parabolic law in most experimental tests under various temperatures.