A combined experimental and computational approach for the design of mold surface topography that leads to desired ingot surface and microstructure in aluminum casting

A comprehensive review will be provided of experimental and computational studies being conducted at Cornell University and Alcoa for the development of a design methodology with which casting mold surface topographies can be tuned to produce required surface features and microstructural properties of aluminum ingots. Both static and continuous casting processes are examined with instrumented molds. Mold surface topographies, which consist of unidirectional and bidirectional groove textures, are generated using contact and non-contact techniques to elicit a radiator-like effect at the mold-casting interface. The rate of heat extraction, the evolution of near-surface cast microstructure, and shell macro morphology can be controlled, once the proper balance between mold surface area extension and the degree of imperfect wetting at the instant solidification starts is determined. Once this control is achieved, it will be possible to minimize or even eliminate costly post-casting surface milling or scalping which is currently a major barrier to the development of new aluminum casting processes.