Analysis of cavity nucleation in solids subjected to external and internal stresses

Journal Article · Fri Mar 01 00:00:00 EST 1985 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(85)90078-1· OSTI ID:5038199

Hirth, J P; Nix, W D

The thermodynamics of cavity nucleation in solids subjected to external and internal stresses are analyzed. We show that the critical nucleus for cavity nucleation can be formed by alternative reversible work paths; either by condensation of pre-existing vacancies or by removal of atoms fro the site of nucleation to sinks within the solid or at the surface. These two nucleation paths are shown to be equivalent. Strain energy terms which are quadratic in stress are found to arise in the free energy of the nucleus when relaxation of the void surface is taken into account. Two different cases of internally stressed solids are treated: one in which vacancy sources and sinks at the site of nucleation are locked and another in which vacancy sources and sinks are unlocked. In the former case the internal stres appears only quadratically or as crossterms in the formation free energy of the critical sized nucleus, while in the latter case, it appears in a linear term, additive to the applied stress, and has a strong effect on cavity nucleation. Problems involving complex nucleus shapes and the effects of plastic relaxation in cavity nucleation are also discussed.

• Research Organization: Department of Metallurgical Engineering. The Ohio State University, Columbus, OH.
• OSTI ID: 5038199
• Journal Information: Acta Metall.; (United States), Vol. 33:3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
METALS
CAVITIES
NUCLEATION
STRESS ANALYSIS
FREE ENERGY
PLASTICITY
STRAINS
STRESS RELAXATION
STRESSES
THERMODYNAMICS
VAPOR CONDENSATION
ELEMENTS
ENERGY
MECHANICAL PROPERTIES
PHYSICAL PROPERTIES
RELAXATION
THERMODYNAMIC PROPERTIES
360103* - Metals & Alloys- Mechanical Properties