Simulation of Cold Compaction Densification Behavior of Silicon Nitride Ceramic Powder

Abstract

The cold‐compaction densification behavior of silicon nitride (Si3N4) ceramic powder was analyzed using two models: the Shima model and the Cam‐Clay model. Triaxial‐compression experimental data were used to evaluate these two models. Shima models that used Si3N4 matrix material with different yield stresses were discussed. It is clear that the Cam‐Clay model can effectively simulate the cold‐compaction densification behavior of Si3N4 ceramic powder. The Shima model that used a very high yield stress for the Si3N4 matrix material slightly overestimated the experimental data, and the Shima model that used the actual yield stress for Si3N4 matrix material largely overestimated that data.

Constitutive Model for Cold Compaction of Ceramic Powder

“…M and ␤ are adjustable constants. Sun et al 3 selected the following parameters for Si 3 N 4 powder: ␤ ϭ 1, K ϭ 1, M ϭ 2.11 and p c ϭ 0.09873 ϩ 638 V rpl Ϫ 2181( V rpl ) 2 ϩ 14996( V rpl ) 3 .…”

“…T HE consolidation or densification of metal and ceramic powders during cold compaction under a combination of hydrostatic and deviatoric stress has been the subject of a number of recent experimental and theoretical studies. [1][2][3][4][5][6][7][8] In near-net-shape production by powder processes the simulation of compaction by a numerical method, for example the finite element method, is essential for considering the various nonlinear conditions such as a complex geometry, inhomogeneous density and temperature distributions, friction, a nonlinear response of the material, and the influence of the container. For adequate simulation of powder compaction by means of continuum mechanics, constitutive equations for the deformation should be properly established.…”

“…Recently, Sun et al 3 investigated the densification of Si 3 N 4 ceramic powder by using the constitutive model of Shima and Mimura 2 and the Cam-Clay model. 4 The Cam-Clay model with three constant parameters and a third order polynomial equation agreed well with the Shima and Mimura experimental data.…”

“…The Shima and Mimura model with four parameters was also shown to be in reasonable agreement with experiment. However, Sun et al, 3 interpreted the parameter S as the yield stress of a matrix material and criticized Shima's calculation for using a value of the S parameter which in their opinion is too high. They concluded that the Shima model which uses the actual yield stress of the matrix should not be used to analyze cold densification behavior at all.…”

Polymer-based graphene composite molding: a review

“…1964-1980Peiyun Huang lg ln ðr m À r 0 Þr ðr m À rÞr 0 ¼ n lg P À lg M m lg ln ðr m À r 0 Þr ðr m À rÞr 0 ¼ lg P À lg M r mending density, r 0initial density, rdensity, Pcompacted strength, Mcompaction modulus, nmm −1 , mhardening index model,69 modied Cam Clay model,70 Mohr-Coulomb model71 and Drucker-Prager/Cap model 72,73. …”