MICROSTRUCTURAL REFINEMENT AND SUPERPLASTICITY OF IN-718 SUPERALLOY

A new thermal and mechanical treatment, based on a cold-work cycle, ab le to promote a superplastic behaviour in the IN-718 superalloy is ill ustrated. The optimum conditions of temperature and strain rate for th e best superplastic behaviour of the alloy have been found. The influe nce of microstructural parameters and the mechanisms involved during t he deformation process are discussed through examination of the flow c urves at various temperatures and strain rates, and by metallographic analyses.