Allvac 718Plus, Superalloy for the Next Forty Years

Abstract

Allvac 718Plus alloy is a new nickel base superalloy, offering excellent mechanical properties, increased temperature capability, good fabricability and moderate cost. This highly desirable combination of characteristics positions the alloy to very effectively fill the longstanding gap between the two most widely used wrought superalloys, 718 and Waspaloy. This paper will review the development of alloy 718Plus, which has progressed over the last eight years, including the effects of chemistry, heat treatment, processing and structure on mechanical properties. The current production status and capability of the alloy will also be discussed along with ongoing applications development. Comparisons will be made to 718, Waspaloy and other superalloys illustrating that alloy 718Plus is the best available candidate to sustain the advances in engine development made possible by the forty-plus year life of alloy 718.