A constitutive model for stage 2 sintering of fine grained materials; 1: Grain boundaries act as perfect sources and sinks for vacancies

Journal Article · Fri Apr 01 04:00:00 EST 1994 · Acta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-7151(94)90138-4· OSTI ID:5091832

Pan, J; Cocks, A C.F. ^[1]

---

1. Cambridge Univ. (United Kingdom). Engineering Dept.

In this paper, a constitutive model for stage 2 sintering of powder compacts by grain-boundary diffusion is established. A three-dimensional material model composed of a uniform array of tetrakaidecahedra shaped grains with spherical pores at each grain-boundary vertex is adopted. A bounding theorem described by Cocks for grain-boundary diffusion problems is used to obtain a lower bound to the scalar strain-rate potential, through which the macroscopic strain rates and macroscopic stresses are related. Use of the theorem requires a set of kinematically compatible fields of grain-boundary separation rates, matter flux along the grain-boundaries and macroscopic strain-rates to be proposed. In this paper, the authors focus their attention on the classical grain-boundary diffusion problem where grain-boundaries are assumed to act as perfect sources and sinks for vacancies.

• OSTI ID: 5091832
• Journal Information: Acta Metallurgica et Materialia; (United States), Journal Name: Acta Metallurgica et Materialia; (United States) Vol. 42:4; ISSN 0956-7151; ISSN AMATEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
BOUNDARY CONDITIONS
CERAMICS
DATA
FABRICATION
INFORMATION
MATHEMATICAL MODELS
NUMERICAL DATA
POWDERS
SINTERING
THEORETICAL DATA