The ductile-brittle size transition of iron aluminide ligaments in an FeAl/TiC composite
- Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.
The fracture surfaces of FeAl/TiC composites containing 70 vol% TiC were investigated. Since thin iron aluminide ligaments in the composites fractured in a ductile manner, whereas thicker ones fractured by cleavage, a systematic correlation of the fracture mode to the ligament thickness was performed. The results clearly show that FeAl ligaments thicker than about 1--2 {micro}m fracture by cleavage and those smaller in size fracture predominantly in a ductile manner. The ductile failure mode is attributed to the limited dislocation pile-up distance available for very thin ligaments, which prevents high stresses from building up and eliminates cleavage fracture. It is also shown that the ductile-brittle transition size is controlled by alloying and/or heat treatment. No significant dependence of the fracture toughness on the fracture mode would be found.
- Sponsoring Organization:
- USDOE, Washington, DC (United States); Oak Ridge Inst. for Science and Education, TN (United States); Oak Ridge National Lab., TN (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 651103
- Journal Information:
- Acta Materialia, Vol. 46, Issue 13; Other Information: PBD: 10 Aug 1998
- Country of Publication:
- United States
- Language:
- English
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