The objective of this proposal is to analytically and experimentally investigate the formation of macro-shrinkage/porosity and micro-porosity in alloy solidification. This is achieved by dividing the research into two steps. In the first step, a numerical technique, based on the finite element method, will be developed for the solution of the conduction heat transfer with phase change. The finite element analysis program which is implemented in this step will be interfaced with the existing geometrical modeling programs to form a CAD/CAM package. The second step is to extend the model to calculations of interdentritic fluid flow in the mushy region during alloy solidification. Both the first model and the second model will be validated by comparing their solutions with experimental measurements as well as with available data in the literature. The metal castings foundry is one of the Nation's oldest industries, but the fundamental understanding of the processes is lacking. The proposed research is expected to make significant contributions not only to the understanding of the formation of macro-shrinkage and micro-porosity of the castings, but also to the design for casting processes for producing sound castings at a lower cost.
