An atom probe field ion microscope investigation of the role of boron in precipitates and at grain boundaries in NiAl
The high resolution analytical technique of Atom Probe Field Ion Microscopy (APFIM) has been used to characterize grain boundaries and the matrix of a stoichiometric NiAl alloy doped with 0.04 (100 wppm) and 0.12 at. % (300 wppm) boron. Field ion images revealed boron segregation to the grain boundaries. Atom probe elemental analysis of the grain boundaries measured a boron coverage of up to 30% of a monolayer. Extensive atom probe analyses also revealed a fine dispersion of nanoscale boride precipitates in the matrix. The boron segregation to the grain boundaries was found to correlate with the observed suppression of intergranular fracture. However, the decrease in ductility of boron-doped NiAl is attributed in part of the precipitation hardening effect of the boride phases.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10110011
- Report Number(s):
- CONF-911202-13; ON: DE92005102
- Resource Relation:
- Conference: Annual fall meeting of the Materials Research Society (MRS),Boston, MA (United States),2-6 Dec 1991; Other Information: PBD: [1991]
- Country of Publication:
- United States
- Language:
- English
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