Studying of Non-Dendritic Microstructure Forming in Controlled Diffusion Solidification

Abstract

A non-dendritic microstructure normally forming the products made by the controlled diffusion solidification process (CDS) has been studied. Samples from Al-4.7 wt%Cu, Al-8 wt%Cu, and Al-4.7 wt%Zn were made via the CDS process by mixing pure aluminum into Al-Cu and Al-Zn binary alloys at a different mass ratio. ANSYS software was employed to predict the distribution of the mixed alloys during the mixing step. The simulation results show that the mixed alloys breakdown to different size pockets. The higher mass pockets fall into the bottom sample after the mixing step resulting in effect the microstructure forming in the entire sample. The experimental results indicate that globular mixed with rosette and dendritic morphologies form the entire microstructure, although all the morphologies were exposed to the same thermal environment during growth. The results show that the globular morphologies form in the undercooled alloy that have a higher liquidus temperature, while the dendritic morphologies form from the alloy that has a lower liquidus temperature, which is heated during the mixing.