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

Journal Article · Fri Oct 01 00:00:00 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]

---

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), Vol. 41:10; ISSN 0956-7151
• Country of Publication: United States
• Language: English

Related Subjects

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