Microstructure and Stress Evolution during Drying of Binary Colloidal Systems

Carlos J. Martinez

Graduate Student

Material Science and Engineering

UIUC

18 November 1999

Microstructural and stress evolution during drying of tape-cast layers derived from binary (Al2O3-Latex) colloidal suspensions were studied. Representative tapes were partially dried, quenched, and the remaining solvent extracted via sublimation to assess the impact of latex coalescence on microstructural evolution during drying. Mercury intrusion porosimetry (MIP) and quantitative image analysis of top surfaces were used to evaluate the pore structure and aggregate size as a function of drying time and suspension composition. MIP measurements reveal that the characteristic pore size decreases with increasing solvent loss. Stress measurements of tape cast layers were carried out using a substrate deflection apparatus under controlled environmental conditions. The maximum drying stress was observed to decrease with increasing ceramic particle size while the latex properties (e.g., Tg) influenced the residual stress.