Microstructure and Microchemistry of Rapidly Solidified Nickel-Base Powders

188 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1982.An investigation of the microstructure and microchemistry of rapidly solidified powders was conducted using transmission electron microscopy in the scanning (STEM) and conventional (CTEM) modes. Using these high resolution techniques, it was possible to study the morphologies of the resultant microstructures and the associated chemical segregation on a very fine scale. Bulk undercooling experiments were also conducted and the microstructures of these samples were compared to those of the rapidly solidified powders. Computer calculations were performed to simulate the solidification of individual powder particles using Newtonian cooling, homogeneous nucleation, and growth theories. The results of these calculations were compared to experimental observations in order to develop an understanding of the mechanisms of solidification in rapidly quenched powders.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD