Diffusion induced grain boundary migration and recrystallization in boron-free Ni[sub 3]Al intermetallics

Journal Article · Tue Mar 15 04:00:00 EST 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90197-X· OSTI ID:5054672

Ma, C Y ^[1]

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1. Max-Planck-Inst. fur Metallforschung, Stuttgart (Germany) Inst. fur Metallkunde, Stuttgart (Germany)

The Ni[sub 3]Al intermetallics, due to their anomalous mechanical behavior and the effect of boron addition on ductility and grain boundary (GB) structure, has received extensive attention in the past decade. In a previous work, diffusion induced grain boundary migration (DIGM) and recrystallization (DIR) in a boron-doped Ni[sub 3]Al(Cu) system were found for the first time, in which an intermetallic compound of Ni[sub 76]Al[sub 24] + 0.22 at. % B was electroplated with Cu and isothermally diffusion-annealed over a temperature range where the volume diffusion occurred in front of the migrating GB. The DIGM velocity, the activation energy for GB migration by DIGM, and the driving force for DIGM in this system were investigated as well. As has been mentioned in the literature, however, boron segregation to grain boundary in Ni[sub 76]Al[sub 24], which is associated with the ductility improvement, might produce a narrow disordered phase at the GB. Recently, this question has been argued, since some researchers did not observe this disordered layer at the GB. On this basis, the DIGM and DIR experiments in boron-free Ni[sub 3]Al should be performed for the purpose of comparison with the results for boron-doped Ni[sub 3]Al. In the present study, two boron-free alloys (Ni[sub 75]Al[sub 25] and Ni[sub 76]Al[sub 24]) were selected. The main objectives were to determine whether or not the phenomena of DIGM and DIR still occur in boron-free Ni[sub 3]Al when Cu and Zn atoms were diffused into them, and, if they exhibited, to examine the chemical changes in the alloyed zones caused by DIGM and DIR.

• OSTI ID: 5054672
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 30:6; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360104 -- Metals & Alloys-- Physical Properties
ALLOYS
ALUMINIUM ALLOYS
ATOM TRANSPORT
COPPER
DIFFUSION
ELEMENTS
GRAIN BOUNDARIES
METALS
MICROSTRUCTURE
NEUTRAL-PARTICLE TRANSPORT
NICKEL ALLOYS
NICKEL BASE ALLOYS
RADIATION TRANSPORT
RECRYSTALLIZATION
TRANSITION ELEMENTS
ZINC