Grain boundary engineering of Allvac 718Plus® for aerospace engine applications

Grain Boundary Engineering (GBE®) and GBE surface treatments (GBEST®) are patent- andvtrademark-protected thermo-mechanical processing technologies that are applicable to a broad range of metals and alloys. The main objective of this study was to extend the applicability of the GBE processing technologies to a more advanced superalloy, Allvac®718Plus®, which is a new derivative of Alloy 718. The specific technical objectives of the study were to: (1) develop and optimize GBE processing strategies for the bulk microstructure of the 718Plus® and (2) develop a processing methodology for locally optimizing the GBE microstructural characteristics at the near-surface region of the alloy. In this paper, the microstructural characteristics achieved from the GBE processing of the 718Plus® alloy are presented. The effect of the GBE processing on the high temperature mechanical properties of the 718Plus® alloy is presented in a separate paper in this symposium proceedings. (AU) © 2010 by The Materials, Metals, & Materials Society. All rights reserved.