Spatial correlation of gamma-prime precipitates in a Ni-Si alloy

Journal Article · Sun Nov 30 23:00:00 EST 1986 · Scr. Metall.; (United States)

DOI:https://doi.org/10.1016/0036-9748(86)90280-2· OSTI ID:6815569

Polat, S; Marsh, C; Little, T; Ju, C P; Epperson, J E; Chen, H

The Ni-Si system is one of the few Ni-based binary alloys that shows negative lattice mismatch between the gamma-prime precipitates and the disordered matrix. The precipitates remain coherent and spherical until their size exceeds 80nm. Recent work has demonstrated that the precipitation kinetics shows a clear transition from the growth period to coarsening in accordance with the Lifshitz-Slyozov-Wagner (LSW) theory of Ostwald ripening. Only two previous reports have shown the preferred alignment of precipitates in Ni-Si at high temperatures after long annealling when precipitates are incoherent and nonspherical. The current work has been undertaken to search for the possible presence of nonrandom arrangement of spherical and coherent precipitates at lower temperatures by a combination of high resolution diffraction using synchrotron radiation, small-angle neutron scattering, and transmission electron microscopy techniques. Diffraction methods are chosen because the modulated and arrangement of coherent precipitates is characterized by diffraction side bands (satellites) in the vicinity of the fundamental Bragg peaks including the forwardly diffracted beam.

• Research Organization: Dept. of Materials Science, Univ. of Illinois, Urbana, IL 61801
• OSTI ID: 6815569
• Journal Information: Scr. Metall.; (United States), Journal Name: Scr. Metall.; (United States) Vol. 20:12; ISSN SCRMB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360101 -- Metals & Alloys-- Preparation & Fabrication
360106* -- Metals & Alloys-- Radiation Effects
AGING
ALIGNMENT
ALLOYS
ANNEALING
BREMSSTRAHLUNG
COHERENT SCATTERING
DIFFRACTION
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELEMENTS
EQUILIBRIUM
GAMMA RADIATION
HEAT TREATMENTS
IONIZING RADIATIONS
MICROSCOPY
MORPHOLOGY
NEUTRON DIFFRACTION
NICKEL ALLOYS
NICKEL BASE ALLOYS
ORIENTATION
PARTICLES
PHYSICAL RADIATION EFFECTS
PRECIPITATION
RADIATION EFFECTS
RADIATIONS
SCATTERING
SEMIMETALS
SEPARATION PROCESSES
SHAPE
SILICON
SILICON ALLOYS
SMALL ANGLE SCATTERING
SPATIAL DISTRIBUTION
SYNCHROTRON RADIATION
TRANSMISSION ELECTRON MICROSCOPY
VOLUME