Grain boundary compositon in NiAl
- Metals and Ceramics Div., Oak Ridge National Lab., Oak Ridge, TN (US)
The high temperature strength and oxidation resistance of many transition metal aluminides makes these intermetallic materials attractive for high temperature applications. However, these aluminides are generally brittle at low temperatures and this restricts their technological applications. However, these aluminides are generally brittle at low temperatures and this restricts their technological applications. It has been demonstrated that the addition of more than 200 ppm of boron to the L1{sub 2}-ordered Ni{sub 3}Al changes the fracture behavior from intergranular to transgranular and increases the ductility. The B2-ordered NiAl nickel aluminide is particularly attractive because of its low density and high melting temperature. This aluminide also fractures intergranularly at room temperature. However, no improvement in ductility is observed with similar boron additions even though the intergranular fracture is suppressed and there is a significant increase in the yield strength. In this paper, the results of an atom probe field ion microscopy investigation of the compositions of the grain boundaries in undoped and boron-doped NiAl are presented. The suitability of the atom probe field ion microscopy technique for the characterization of boundaries has clearly been demonstrated in many previous investigations including the characterization of boron segregation to grain boundaries and other planar features in Ni{sub 3}Al.
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 5703669
- Journal Information:
- Scripta Metallurgica; (United States), Journal Name: Scripta Metallurgica; (United States) Vol. 26:4; ISSN 0036-9748; ISSN SCRMB
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
360104 -- Metals & Alloys-- Physical Properties
360105 -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
BORON ADDITIONS
BORON ALLOYS
CHEMICAL COMPOSITION
CRYSTAL STRUCTURE
DENSITY
DOPED MATERIALS
DUCTILITY
FRACTURE PROPERTIES
GRAIN BOUNDARIES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
TENSILE PROPERTIES
YIELD STRENGTH