SYMPOSIA PAPER Published: 01 January 2000

The Fracture and Fatigue Crack Growth Behavior of Forged Damage-Tolerant Niobium Aluminide Intermetallics


The micromechanisms of fracture and fatigue crack growth are elucidated for a new class of damage-tolerant niobium aluminide Nb3Al-xTi intermetallics. Fatigue crack growth in alloys containing 10 and 25 at% Ti is shown to occur primarily by cleavage, while alloys containing ∼40 at% Ti are shown to exhibit similar fracture and fatigue crack growth behavior to ductile metals and their alloys. Slower elevated-temperature (750°C) crack growth rates in the Nb3Al-40Ti alloy are attributed largely to the effects of oxide-induced crack closure. The transition from cleavage fracture (in the Nb3Al-10Ti and Nb3Al-25Ti alloys) to ductile fracture in the Nb3Al-40Ti is correlated with the onset of significant levels of crack-tip plasticity, which is predicted using atomistic simulations.

Author Information

Ye, F
The Ohio State University, Columbus, OH
Mercer, C
The Ohio State University, Columbus, OH
Farkas, D
Virginia Polytechnic Institute and State University, Blacksburg, VA
Soboyejo, WO
Princeton University, Princeton, NJ
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: E08
Pages: 278–298
DOI: 10.1520/STP13409S
ISBN-EB: 978-0-8031-5418-6
ISBN-13: 978-0-8031-2617-6