Crack propagation in NiAl and FeAl

Conference · Thu Dec 31 04:00:00 EST 1992

OSTI ID:10130616

Schneibel, J H; Jenkins, M G; Maziasz, P J

The crack-propagation behavior and fracture toughness at room temperature of extruded and heat-treated NiAl and FeAl were examined by testing chevron-notched, three-point flexural specimens at constant crosshead speeds. In Ni-50 at. % Al, sudden load drops occurred repeatedly, indicating run-arrest crack propagation. The fracture resistance was not found to depend ci the crosshead speed. Iron additions of up to 1 at. % and boron additions of 0.01 at. % did generally not improve the fracture toughness. By contrast, crack propagation in Fe-40 at. % Al occurred in a stable manner. In agreement with the environmental sensitivity of this intermetallic alloy, fracture resistance did depend on the crack-propagation velocity, indicative of the kinetic nature of this process. While the crack-growth resistance of iron aluminides was reduced by changing the aluminum content from 40 to 45 at. %, it was increased significantly by small additions of boron.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 10130616
• Report Number(s): CONF-921101--84; ON: DE93007244
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103
ALUMINIUM ALLOYS
BORON ADDITIONS
CRACK PROPAGATION
FRACTURE PROPERTIES
IRON ALLOYS
MECHANICAL PROPERTIES
NICKEL ALLOYS