Solute embrittlement of SiC

Journal Article · Sun Sep 21 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4895841· OSTI ID:22305989

Enrique, Raúl A., E-mail: [e-mail] ^[1]; Van der Ven, Anton, E-mail: [e-mail] ^[2]

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1. Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48103 (United States)
2. Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

The energies and stresses associated with the decohesion of β-SiC in the presence of mobile Pd and Ag impurities are studied from first principles. Density functional theory calculations are parameterized with a generalized cohesive zone model and are analyzed within a thermodynamic framework that accounts for realistic boundary conditions in the presence of mobile impurities. We find that Pd impurities will embrittle SiC when Pd is in equilibrium with metallic Pd precipitates. Our thermodynamic analysis predicts that Pd embrittles SiC by substantially reducing the maximum stress of decohesion as a result of a phase transition between decohering planes involving an influx of Pd atoms. The methods presented in this work can be applied to study the thermodynamics of decohesion of SiC in other aggressive environments containing oxygen and water, for example, and yield environment dependent cohesive zone models for use in continuum approaches to study crack propagation and fracture.

• OSTI ID: 22305989
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BOUNDARY CONDITIONS
COMPUTERIZED SIMULATION
CRACK PROPAGATION
DENSITY FUNCTIONAL METHOD
EMBRITTLEMENT
EQUILIBRIUM
FRACTURES
IMPURITIES
OXYGEN
PALLADIUM ADDITIONS
PHASE TRANSFORMATIONS
PRECIPITATION
SILICON CARBIDES
SILVER ADDITIONS
SOLUTES
STRESSES
THERMODYNAMICS