6533b7d9fe1ef96bd126ca3d
RESEARCH PRODUCT
Small-Angle Scattering from Phase-Separated Metallic Alloys: From Experiment to Phase Diagrams
G. PipitoneMichele FlorianoEugenio CaponettiRoberto Triolosubject
Metallic alloyMaterials scienceScatteringTransmission electron microscopyDispersitySmall-angle scatteringAtomic packing factorSmall-angle neutron scatteringMolecular physicsPhase diagramdescription
In this paper, phase-separated metallic alloys are described in terms of concentration fluctuations. As a consequence, Small Angle Scattering equations which allow to calculate the entire scattering curve by incorporating particle-particle interference effects on the basis of the Percus-Yevick formalism, are obtained. It is shown that, for Aluminium-Lithium alloys, satisfactory fits of the experimental data can be obtained if it is assumed that Li rich elliptical monodisperse precipitate particles approach each other at average distances which are larger than the sum of the hard-sphere particle radii. It is also shown that a possible ambiguity of this model, within the Percus-Yevick formalism, can be avoided if the particle-particle interaction potential is assumed to be the sum of a hardsphere part plus a finite repulsive step. Small Angle Scattering techniques are important when structural information is needed in the early stages of the phase decomposition, and is complementary to the more widely used Transmission Electron Microscopy, the ideal technique when the size of the fluctuation regions is of the order of 100 nm or larger.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1994-01-01 |