Computational Modeling of Fugitive Phase Rotations Within Tape Cast Ceramics

For complex ceramic parts, new fabrication methods, such as the fugitive phase approach, are required. A common problem in the creation of ceramic parts is obtaining accurate dimensions of the final part. The sintering process makes it very difficult to create precise complex geometries. Tolerances achieved with green ceramics do not carry over to acceptable tolerances on the finished part due to non-uniform shrinkage and warping. The authors are investigating the application of the fugitive phase processing method, which might be able to fabricate topologically complex monolithic ceramic parts with precise tolerances. This paper is a continuation of previous work and examines the lamination step of the fugitive phase approach ceramic fabrication process; the step in which the fugitive phase material is integrated with the green ceramic material. In this step, the pressing along with the geometric layout of the fugitive phase material create an uneven pressure distribution in the green ceramic. Of particular concern is the rotation of the fugitive phase materials during the lamination step. A computational model of the lamination process is used to examine how the plasticity of the fugitive phase material along with computational boundary conditions affect the geometry of the green ceramic produced at the end of the lamination step prior to sintering. The resulting stress, strain energy, and deformed shapes are examined and compared. This information will be used to adjust the experimental investigations of the fugitive phase approach ceramic fabrication process that is working to create topologically complex ceramic components.