An Energy Based Approach Toward Determining Part Shape Change During the Sintering of Ceramic Parts

Abstract

Part distortion during sintering results from nonhomogeneous and nonisotropic shrinkage. Shrinkage is highly dependent on density and particle size distributions within a part, thus, “shrinkage factors” are not constant and may vary throughout the part. An energy based approach is presented which can be used to form accurate shrinkage laws for eventual use in a finite element solution of part shape change. This energy method can be easily modified to include the important effects of particle size variations, contact forces and irregular particle shape in the formation of accurate of shrinkage laws. Linear particle shrinkage and rotations due to contact stresses are examined using simple two particle geometries to test the validity of the approach. Energy methods give results which agree well with observation and the direct application of the diffusion equation, however, the advantage of this formulation over traditional diffusion based analysis will be fully realized in the eventual task of specifying time dependent shrinkage laws of realistic multi particle models.