Computer simulation of atomic ordering and compositional clustering in the pseudobinary Ni{sub 3}Al-Ni{sub 3}V system

Journal Article · Mon Mar 02 04:00:00 EST 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(97)00335-2· OSTI ID:616397

Poduri, R; Chen, L Q ^[1]

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

The kinetics of diffusional phase transformations in the pseudobinary Ni{sub 3}Al-Ni{sub 3}V system were studied using a computer simulation technique based on microscope diffusion equations. The focus is on the initial stages of atomic ordering and compositional clustering process during the phase transformation of an initially homogeneous disordered f.c.c. ternary alloy (Ni{sub 75}Al{sub 25{minus}x}V{sub x}) into a two-phase mixture of L1{sub 2} (Ni{sub 3}Al) and DO{sub 22} (Ni{sub 3}V) ordered phases. A thermodynamic model is proposed to describe the phase equilibria in this pseudobinary system. The computer simulations demonstrated that at small vanadium content, the L1{sub 2} ordered domains appear first, followed by the nucleation of DO{sub 22} ordered domains at the antiphase domain boundaries of L1{sub 2}, whereas at large vanadium content, precipitation of DO{sub 22} precedes L1{sub 2} domain formation. The simulation results are discussed employing the thermodynamic stability analysis. The ordering and clustering kinetics predicted the computer simulation are consistent with recent experimental observations.

• OSTI ID: 616397
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 5 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
MATHEMATICAL MODELS
MICROSTRUCTURE
NICKEL BASE ALLOYS
ORDER-DISORDER TRANSFORMATIONS
PRECIPITATION
VANADIUM ALLOYS