Interfacial fracture mechanisms in solid solution directionally solidified eutectic oxide composites
The interfacial fracture behavior of the solid solution directionally solidified eutectic oxide, Co{sub 1-x}Ni{sub x}O/ZrO{sub 2}(CaO), is investigated via indentation testing. An abrupt transition from interfacial delamination to interfacial penetration is observed as a function of NiO fraction (x>0.33). The use of a focused ion beam technique is introduced as a means for exploring sub-surface cracking in brittle materials. The sub-surface observations revealed a compositional transition from energy dissipative mechanisms (e.g., delamination, secondary cracking) for cracking to brittle cracking behavior, in the Co{sub 1-x}Ni{sub x}O phase. It is proposed that the transition in interfacial fracture behavior for the directionally solidified eutectic material is the result of competing dislocation-based crack nucleation mechanisms. The observations and analyses have significant implications for fracture behavior in composites with one phase exhibiting (pseudo-) plastic behavior.
- OSTI ID:
- 20634729
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 13 Vol. 52; ISSN 1359-6454; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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