Microstructures and hardness of ultrafine-grained Ni[sub 3]Al

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(93)90110-E· OSTI ID:6256168

Languillaume, J; Chmelik, F; Kapelski, G; Bordeaux, F; Nazarov, A A; Canova, G; Valiev, R Z; Baudelet, B ^[1]; Esling, C ^[2]

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1. Inst. National Polytechnique de Grenoble (France). Genie Physique et Mecanique des Materiaux
2. Univ. de Metz (France). Lab. de Metallurgie des Materiaux Polycristallins

The microstructural evolution of the ultrafine-grained intermetallic compound Ni[sub 3]Al is studied as a function of annealing at different temperatures. The ultrafine microstructure is produced by a high plastic torsional straining. Transmission electron microscopy, X-ray diffraction and differential scanning calorimetry are used to characterize the microstructural evolution and microhardness is used to determine mechanical behavior. The as-deformed microstructure exhibits an almost fully disordered crystalline structure with coherent domain size of about 18 nm, a strong torsional texture and high internal elastic strains. On annealing the as-deformed samples at different temperatures, the recrystallization of the material into a granular type structure containing non-equilibrium grain boundaries is first observed. This is followed by the transformation from non-equilibrium into equilibrium grain boundaries with simultaneous grain growth. This transformation is correlated with an increase of hardness. A new concept of non-equilibrium grain boundaries transparency is presented to interpret this singular behavior. The results are compared to those obtained on an ultrafine-grained Al-1.5% Mg alloy produced by the same technique and which exhibits the same mechanical behavior.

• OSTI ID: 6256168
• Journal Information: Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 41:10; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
BINARY ALLOY SYSTEMS
CALORIMETRY
COHERENT SCATTERING
DEFORMATION
DIFFRACTION
ELECTRON MICROSCOPY
HARDNESS
INTERMETALLIC COMPOUNDS
MECHANICAL PROPERTIES
MICROSCOPY
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
RECRYSTALLIZATION
SCATTERING
STRAINS
TEXTURE
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION