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A Numerical Model for Powder Densification by SPS Technique
Author(s) -
Mondalek Pamela,
Silva Luisa,
Bellet Michel
Publication year - 2011
Publication title -
advanced engineering materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 114
eISSN - 1527-2648
pISSN - 1438-1656
DOI - 10.1002/adem.201000340
Subject(s) - materials science , porosity , intermetallic , constitutive equation , microstructure , spark plasma sintering , compaction , sintering , finite element method , powder metallurgy , near net shape , porous medium , composite material , thermal , mechanics , thermodynamics , physics , alloy
Spark plasma sintering (SPS) belongs to a class of sintering techniques that employs electric current to assist compaction. This technology seems very promising to obtain net‐shape components made of intermetallic alloys with a fine microstructure. However, the SPS process is difficult to stabilize because of density heterogeneities arising from non‐homogeneous temperature or stress in the powder. This motivates the development of a three‐dimensional finite element simulation in order to understand the distribution of current, temperature and porosity. The model couples three physical problems: electrical, thermal and mechanical. The numerical implementation is based on a monolithic formulation consisting in solving the different conservation equations on a single mesh including the specimen and the tooling. The general set of equations is described; the effect of the powder physical properties and of the geometry of the set up on the distribution of electrical current and temperature is discussed. A macroscopic Abouaf constitutive model is used to simulate powder densification; first results involving porosity evolution are presented.