An in situ USAXS-SAXS-WAXS study of precipitate size distribution evolution in a model Ni-based alloy

Intermetallic γ' precipitates typically strengthen nickel-based superalloys. The shape, size and spatial distribution of strengthening precipitates critically influence alloy strength, while their temporal evolution characteristics determine the high-temperature alloy stability. Combined ultra-...

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Veröffentlicht in:Journal of applied crystallography. - 1998. - 50(2017), Pt 3 vom: 01. Juni, Seite 734-740
1. Verfasser: Andrews, Ross N (VerfasserIn)
Weitere Verfasser: Serio, Joseph, Muralidharan, Govindarajan, Ilavsky, Jan
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2017
Zugriff auf das übergeordnete Werk:Journal of applied crystallography
Schlagworte:Journal Article Bayesian inverse transformation USAXS–SAXS–WAXS precipitation hardening small-angle X-ray scattering ultra-small-angle X-ray scattering wide-angle X-ray scattering
Beschreibung
Zusammenfassung:Intermetallic γ' precipitates typically strengthen nickel-based superalloys. The shape, size and spatial distribution of strengthening precipitates critically influence alloy strength, while their temporal evolution characteristics determine the high-temperature alloy stability. Combined ultra-small-, small- and wide-angle X-ray scattering (USAXS-SAXS-WAXS) analysis can be used to evaluate the temporal evolution of an alloy's precipitate size distribution (PSD) and phase structure during in situ heat treatment. Analysis of PSDs from USAXS-SAXS data employs either least-squares fitting of a preordained PSD model or a maximum entropy (MaxEnt) approach, the latter avoiding a priori definition of a functional form of the PSD. However, strong low-q scattering from grain boundaries and/or structure factor effects inhibit MaxEnt analysis of typical alloys. This work describes the extension of Bayesian-MaxEnt analysis methods to data exhibiting structure factor effects and low-q power law slopes and demonstrates their use in an in situ study of precipitate size evolution during heat treatment of a model Ni-Al-Si alloy
Beschreibung:Date Revised 30.09.2020
published: Electronic-eCollection
Citation Status PubMed-not-MEDLINE
ISSN:0021-8898
DOI:10.1107/S1600576717006446