engleski

Modeling of relation between corrosive acidic media parameters and bulk density of sintered highly pure alumina using Box-Behnken design

Sintering process has one of the key roles in achieving the density close to the theoretical density. Sintering may be conducted by conventional and nonconventional sintering method. Density level obtained by certain sintering method and regime might be changed by the exposure of material to highly corrosive media. Furthermore, final product’s performance and lifespan might be determined by the corrosive media-ceramic interaction. Impact of acidic media on density of highly pure aluminium oxide (Al2O3) sintered by conventional (electric kiln) and non-conventional (hybrid microwave kiln) sintering method was explored. Effects of nitric acid (HNO3) concentration (0.5, 1.25 and 2 mol dm-3), temperature (25, 40 and 55 °C) and exposure time (24, 132 and 240 h) on bulk density of alumina were statistically investigated by using Box-Behnken design. Bulk density was determined before and after the corrosion in aqueous solution of HNO3 by the Archimedes' method. Bulk density results underwent statistical analysis (ANOVA). Equations for bulk density of corroded conventionally and non-conventionally sintered ceramics were generated which enabled estimation of the theoretical values for applied conditions. The statistical analysis showed also the most significant factors that have an impact on the ceramic’s corrosion, which occurred to be temperature and concentration, no matter on sintering method applied.

alumina ceramic ; Box-Behnken design ; density ; sintering method

nije evidentirano