Effects of grain size on the strength and ductility of Ni sub 3 Al and Ni sub 3 Al + boron

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5449966

Viens, D V; Weihs, T P; Baker, I; Schulson, E M ^[1]

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1. Dartmouth College, Hanover, NH (USA)

Tensile and compression experiments have been performed on Ni{sub 3}Al and on Ni{sub 3}Al + B at 77K to 1023K at 1 {times} 10{sup {minus}4}s{sup {minus}1}. At low temperatures yielding occurs discontinuously and the yield strength obeys the relationship {sigma}{sub y} = {sigma}{sub i} + kd{sup {minus}3/4} where {sigma}{sub i} and k are constants. Grain refinement has little effect on the ductility of the binary alloy, but leads to a brittle to ductile transition in the alloy containing boron. At high temperatures, grain refinement weakens the material, owing to grain boundary sliding. Dynamic recrystalization occurs and leads to another brittle to ductile transition upon refining the grains. Under all conditions investigated, fracture occurs intergranularly. An analysis based upon a work-hardening model is given for the d{sup {minus}3/4} dependence of the yield strength at low temperatures.

• OSTI ID: 5449966
• Report Number(s): CONF-840909-; CODEN: TMPSA
• Journal Information: TMS (The Metallurgical Society) Paper Selection; (USA), Vol. 56; Conference: TMS-AIME fall meeting, Detroit, MI (USA), 16-20 Sep 1984; ISSN 0197-1689
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
GRAIN SIZE
MECHANICAL PROPERTIES
NICKEL ALLOYS
BINARY ALLOY SYSTEMS
BORON ADDITIONS
BRITTLE-DUCTILE TRANSITIONS
COMPRESSION STRENGTH
DUCTILITY
EQUATIONS
FRACTURES
GRAIN BOUNDARIES
RECRYSTALLIZATION
SLIP
STRAIN HARDENING
TENSILE PROPERTIES
YIELD STRENGTH
ALLOY SYSTEMS
ALLOYS
BORON ALLOYS
CRYSTAL STRUCTURE
FAILURES
HARDENING
MICROSTRUCTURE
SIZE
360103* - Metals & Alloys- Mechanical Properties
360102 - Metals & Alloys- Structure & Phase Studies