Rotating strength of forged TiAl alloys

In order to evaluate the rotating strength of TiAl alloys, mechanical and rotating burst testing were conducted on wrought TiAl having various microstructures. The rotating burst strength of the nearly lamellar (NL) structure was greater than near gamma (NG) or fully lamellar (FL)structures. The mechanical properties which have an affect on the rotating strength were yield strength and elongation, and only a slight amount of elongation allows the rotating burst characteristics of TiAl alloys to change from ceramic-like maximum stress dependency to metal-like mean stress dependency. It was estimated that forged NL-TiAl has greater rotating strength above 1000 K than superalloys in current use. (C) 1999 Elsevier Science Ltd. All rights reserved.