Effect of solids loading and dispersant concentration on strain mismatch and deformation of slip-cast green bodies

A method has been developed to identify low levels of strain mismatch prese nt in bodies in the green state. High-aspect-ratio beams of alumina were sl ip cast at 35-50 vol% solids over a range of poly(acrylic acid) concentrati ons. After sintering in an unconstrained manner, the beams deform into an a re. The magnitude and direction of curvature was observed to depend on both the solids loading and the concentration of polyelectrolyte. Model calcula tions indicate that strain mismatch within the beams of 1%, which correspon ds to green density variations of up to 2.5%, would account for the observe d degree of bending. The direction of bending was rationalized in terms of the competing effects of cake compressibility and particle velocity.