Toughness as a function of thermo-mechanical processing and heat treatment in 718plus® superalloy

ATI 718Plus® Alloy is a new cost-effective superalloy which fills the gap in temperature capability between 718 and Waspaloy nickel alloys. The effect of thermal mechanical processing and heat treatment on the room temperature impact toughness and fracture toughness of ATI 718Plus® Alloy has been evaluated. Fractography, microscopy and tensile testing were used to determine the microstrucutral features associated with high toughness. Impact toughness was measured with Charpy V-notch samples, while fracture toughness was determined using three point bend samples. The observed toughness was comparable to Alloy 718. Grain boundary delta phase was found to have the most significant influence on toughness where its presence had a net negative affect. (AU) © 2010 by The Materials, Metals, & Materials Society. All rights reserved.