Dynamic Compaction of Rapidly Solidified Nickel-Base Superalloys (Rapid Solidification, Powder Metallurgy, Hot Isostatic Pressing, Consolidation, Precipitation)

170 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1986.Rapid solidification of an experimental nickel-base superalloy was achieved using centrifugal atomization, chill-block melt-spinning and laser surface melting. Transmission electron microscopy was utilized to characterize the various microstructures obtained in terms of growth morphology, segregation profiles, (gamma)' size and distribution of secondary hardening phases. The response of melt-spun ribbon to thermal treatment was determined and utilized to evaluate the microstructures observed in consolidated material.Rapidly solidified particulate was consolidated using both hot isostatic pressing and dynamic powder compaction. Studies were conducted to establish the way in which rapidly solidified microstructures had changed during each process, particularly with respect to possible interparticle bonding mechanisms. Mechanical tests performed on the hot isostatically pressed material established the integrity of this bonding. In addition, the dynamically compacted material was exposed to various elevated temperatures to determine the stability of the microstructure. The resultant recrystallized microstructure was evaluated in terms of the suitability of the material for intermediate temperature applications.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD