Rapid solidification studies of Ni/sub 3/Al alloys

Conference · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6601786

Koch, C C; Horton, J A; Liu, C T; Cavin, O B; Scarbrough, J O

Rapidly solidified foils of Ni/sub 3/Al (24 at. % Al) with and without additions of boron (500 and 1000 wt ppM) were prepared in an arc-hammer apparatus. The bend ductility, microhardness, and microstructure of the foils were studied as a function of solidification rate, which was defined by foil thickness. Boron-free Ni/sub 3/Al samples exhibited brittle behavior over the entire range of solidification rates used (foil thicknesses 20 to 100 ..mu..m). However, boron-containing samples, which were ductile for foil thicknesses greater than 45 ..mu..m showed a transition-to-brittle behavior in the range of thickness of 30 to 45 ..mu..m. The high hardness of the rapidly quenched foils (450 DPN) remained approximately constant in this transition range. Electron microscopy revealed a complex anti-phase boundary (APB) structure that could not be correlated to the mechanical behavior. The suppression of the beneficial boron segregation to grain boundaries is believed to be responsible for the ductile-to-brittle transition on increasing solidification rate. 5 figures.

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6601786
• Report Number(s): CONF-821223-2; ON: DE83004648
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
BENDING
BORON ADDITIONS
BORON ALLOYS
CRYSTAL STRUCTURE
DIMENSIONS
DUCTILE-BRITTLE TRANSITIONS
DUCTILITY
ELECTRON MICROSCOPY
FOILS
HARDNESS
INTERMETALLIC COMPOUNDS
MECHANICAL PROPERTIES
MICROHARDNESS
MICROSCOPY
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
PHASE TRANSFORMATIONS
SEGREGATION
SOLIDIFICATION
TENSILE PROPERTIES
THICKNESS