Solidification and solid state phase transformation of Allvac® 718Plus™ alloy

Abstract

Solidification and solid state transformations of Allvac® 718Plus™ alloy were studied by modeling and experiment. Solidification behavior was investigated by DTA and SEM/EDS techniques and compared with modeling calculations. Various phases were identified and formation of the cast structure was interpreted on the basis of a pseudo-binary phase diagram developed in this work. The chemistry, crystal structure and growth rate of hardening phases and their precipitation kinetics were studied. Aging behavior and the effect of solution temperature and plastic deformation were addressed. Special attention was paid to δ phase precipitation. The nature, morphology and formation kinetics of δ phase were investigated and its effect on mechanical properties are discussed.