Ph.D. Proposal Presentation by Tracie Zoeller
Monday, July 14, 2003

(Drs. Paul Neitzel and Thomas Sanders, Jr., co-advisors)

"Modeling Microstructural Evolution in Aluminum Alloys"

Abstract

Throughout the processing of an aluminum alloy, prior microstructures affect subsequent microstructural evolution. Variation in local composition may promote or hinder precipitation of new phases. Pre-existing particles may enhance nucleation of new phases by heterogeneous nucleation. Local composition controls subsequent microstructures and the overall properties of the final product. Secondary phases may form in a heterogeneous fashion due to local composition fluctuations. An uneven distribution of secondary phases is detrimental to the final product and may be difficult to detect at the macroscopic level. Failure can occur in industrial parts as a result of a heterogeneous microstructure. Thus, a more complete understanding of microstructural evolution is important.

The goal of this research is to develop a quantitative model to predict the microstructural evolution of a complex, precipitation hardening aluminum alloy during thermal processing. The model will be a useful tool in developing better, stronger alloys. Important aspects of an alloys progression that will be considered in this proposed research include microsegregation in dendrite arms and the effects of precipitate growth and dissolution. A variety of physical parameters will be required for this proposed research and will be determined experimentally.