EFEITO DE MÚLTIPLOS CICLOS DE SOLUBILIZAÇÃO SUB-SOLVUS DELTA E ENVELHECIMENTO NA MICROESTRUTURA E PROPRIEDADES MECÂNICAS DA SUPERLIGA 718

Abstract

In the present work, forged and cast samples of superalloy 718, from an aircraft engine, were submitted to multiple cycles of solution annealing and aging, being the solution annealing in a sub-solvus δ temperature, inducing an increasing quantity of this phase with the number of heat treatment cycles. Through quantification of δ phase using scanning electron microscopy, tensile tests and X-ray diffraction after the heat treatment cycles, it was possible to observe an increasing fraction and particle size of δ phase, with a consequent reduction in the strength, which can be associated with less Nb available in the matrix for the precipitation of the hardening phase, γ". (English) [ABSTRACT FROM AUTHOR]