Texture and grain boundary character distribution in recrystallized Ni[sub 3]Al sheets

Journal Article · Wed Jun 01 00:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90237-2· OSTI ID:7303367

Lin, H; Pope, D P ^[1]

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1. Univ. of Pennsylvania, Philadelphia, PA (United States). Dept. of Materials Science and Engineering

It has been experimentally demonstrated that in Ni[sub 3]Al (without boron) only two kinds of grain boundaries are especially strong, symmetrical [Sigma]3 boundaries and low angle boundaries. Columnar Ni[sub 3]Al polycrystals containing mostly low angle and [Sigma]3 boundaries (over 70%) are highly ductile. Additionally, new results are now available on the ductility of B-free and defect free Ni[sub 3]Al polycrystals produced by cold working and recrystallizing Ni[sub 3]Al single crystals: there is a dramatic increase in ductility when the B-free, defect-free specimens are tensile tested in dry oxygen and vacuum, but there is only a negligible increase in ductility when tensile tested in air. An environmental effect has been cited as the reason for this phenomenon, but it is not clear whether the special processing technique brings about an increase in the fraction of strong boundaries and if so, whether that increase is sufficient to affect an increase in ductility in dry oxygen. Based on the above considerations the authors proceeded to study the distribution of strong boundaries in similarly-produced polycrystalline material. The term Grain Boundary Character Distribution (GBCD) is often used to describe the distribution of grain boundaries classified according to [Sigma] value. Although the correlation between mechanical properties and [Sigma] value has not been firmly established except for low angle boundaries and [Sigma]3 symmetrical boundaries, the GBCD is still a valuable parameter and is used in this work since the last two types of boundaries usually constitute a significant portion of the total boundaries. In this work they report their experimental findings on the texture and GBCD of a thin sheet of Ni[sub 3]Al produced by cold working and recrystallizing a single crystal and discuss whether the changes in GBCD are responsible for the improved ductility of similarly produced Ni[sub 3]Al polycrystals.

• OSTI ID: 7303367
• Journal Information: Scripta Metallurgica et Materialia; (United States), Vol. 30:11, Issue 11; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
DUCTILITY
GRAIN BOUNDARIES
TEXTURE
NICKEL BASE ALLOYS
EXPERIMENTAL DATA
INTERMETALLIC COMPOUNDS
ALLOYS
DATA
INFORMATION
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NUMERICAL DATA
TENSILE PROPERTIES
360102* - Metals & Alloys- Structure & Phase Studies
360103 - Metals & Alloys- Mechanical Properties