A cavity nucleation model during high temperature creep deformation of metals

• Published in: Acta metallurgica et materialia Vol. 41; no. 2; pp. 539 - 542
• Main Authors: Xinggang, Jiang, Jianzhong, Cui, Longxiang, Ma
• Format: Journal Article
• Language: English
• Published: Tarrytown, NY Elsevier B.V 01.02.1993; Pergamon Press
• Subjects: 360103 - Metals & Alloys- Mechanical Properties; Applied sciences; CAVITIES; Condensed matter: structure, mechanical and thermal properties; CREEP; CRYSTAL DEFECTS; CRYSTAL MODELS; CRYSTAL STRUCTURE; DEFORMATION; DISLOCATIONS; ELEMENTS; Exact sciences and technology; LINE DEFECTS; MATERIALS SCIENCE; MATHEMATICAL MODELS; Mechanical and acoustical properties of condensed matter; MECHANICAL PROPERTIES; Mechanical properties of solids; METALS; Metals. Metallurgy; NUCLEATION; Physics; STRESS INTENSITY FACTORS; Grain size; Stress concentration; Nucleation; Creep; Vacancy; Theoretical study; Metal; Dislocation; Young modulus; Theoretical model; Cavity; Creep deformation; Surface energy
• ISSN: 0956-7151; 1873-2879
• DOI: 10.1016/0956-7151(93)90083-5

Based on previous theoretical models of cavity nucleation during creep deformation, a new cavity nucleation model is proposed in this paper. The basic idea of this new model is that cavity nucleation during creep deformation depends not only on the stress concentration of a piled-up group of dislocations but also vacancy clustering. The new equation for the critical radius of cavity nucleation is as follows, r c = (2 γ/ σ ∞) − (2 d/3 E) σ ∞ where r c is the critical radius of cavity nucleation, γ is the surface energy, σ ∞ is the remote applied stress, d is the grain size and E is Young's modulus. When the applied stress is small enough, the equation can be simplified to r c = 2 γ/ σ ∞ , which was proposed by Raj et al. In the limit, when the applied stress σ ∞ is large enough, the critical radius goes to zero and the upper bound stress for cavity nucleation can be obtained, which is very similar to that proposed by Smith et al.