Selection of heat treatment parameters for a cast Allvac 718plus® alloy

The first selection of best set of parameters for heat treating a cast Allvac 718Plus alloy is presented in this paper. The high interest from several aeroengine manufacturers in this new alloy with improved temperature capabilities over widely used In718 has driven the devel pment of the alloy also in the direction of making available a cast form of it. A first step in this drection was to use some available material (billet originally intended to be used for forging other parts) as remelting stock for producing a couple of cast rings and use them as test material for assessment of different sets of heat treatment parameters. In particular, the application of homogenization before HIP and the solution temperature after HIP are discussed. Use of hardness measurements and optical microscopy were made to help in the assessment of the effect of the homogenization cycle, and also the effect of the different solution temperatures. Other techniques such as Scanning Electron Microscope and X-Ray Diffraction were tr ed for identification and quantification of hardening phases. (AU) © 2010 by The Materials, Metals, & Materials Society. All rights reserved.