Influence of Interface Proximity on Precipitation Thermodynamics

The formation of coherent precipitates is often accompanied by large elastic mismatch stresses, which suppress phase separation. We discuss the presence of interfaces as a mechanism for stress relaxation, which can lead to preferred zones of precipitation. In particular, we discuss the proximity of...

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Bibliographic Details
Main Authors: Kai Wang, Marc Weikamp, Mingxuan Lin, Carina Zimmermann, Ruth Schwaiger, Ulrich Prahl, Martin Hunkel, Robert Spatschek
Format: Article
Language:English
Published: MDPI AG 2020-09-01
Series:Metals
Subjects:
Online Access:https://www.mdpi.com/2075-4701/10/10/1292
Description
Summary:The formation of coherent precipitates is often accompanied by large elastic mismatch stresses, which suppress phase separation. We discuss the presence of interfaces as a mechanism for stress relaxation, which can lead to preferred zones of precipitation. In particular, we discuss the proximity of free surfaces and shear-coupled grain boundaries, for which we can obtain a substantial local energy reduction and predict the influence on the local precipitation thermodynamics. The latter case is accompanied by morphological changes of the grain boundary, which are less suitable for large-scale descriptions. For that purpose, we develop an effective description through an elastic softening inside the grain boundary and map the microscopic grain boundary relaxation to a mesoscopic elastic and phase field model, which also allows generalizing the description to multi-phase situations.
ISSN:2075-4701