A numerical analysis of cold powder compaction based on micromechanical experiments

Abstract

The Discrete Element Method (DEM) is used for predicting the compaction behavior of two types of spray dried cemented carbide granules. The material model of the granules is determined by micromechanical experiments. Firstly, compression tests are made on single granules giving information of the deformation behavior at relatively small deformations. For larger deformations, nanoindentation tests are made to give further information of the constitutive behavior which shows a strong hardening behavior at high strains.The material model is implemented in a FE model of two particles in contact and the relation between contact force and indentation depth is exported to a DEM program. The DEM program is used to simulate presently performed uniaxial die compaction experiments where the geometry of the die is taken into account. Excellent agreement is found between the experiments and the numerical predictions in the range where results from DEM simulations are valid.

Analysis of compaction in brittle foam with multiscale indentation tests

“…A similar dependence was obtained for porous rocks [17], cemented carbide [29] and plaster [30,27]. The aim of the following sections is to explain the (linear) macroscopic load vs. depth penetration response.…”

On the Influence of Material Parameters in a Complex Material Model for Powder Compaction

“…Concerning the stresses at maximum compaction as analyzed in this paper, the three material parameters with the largest Fig . 9 Influence from variables defined in Table 1, related to the relative density d (density divided by sintered density), at maximum compaction of Insert [1][2][3][4] influence are the same as in (Ref 12). Especially for Insert 4 with a thin shape that in some sense behaves as the instrumented thin cylinder during compaction, the influence from the different parameters is very similar.…”

Determination of the Frictional Behavior at Compaction of Powder Materials Consisting of Spray-Dried Granules

“…Together with the results presented in previous research (Ref 6,[16][17][18], it is believed that future FE simulations will give relevant results for the press tool compensations mentioned above. Both FE simulations of powder compaction (Ref 5,19,20) as well as simulations using the discrete element method (DEM) (Ref [21][22][23][24] can in the future gain from the present results.…”

“…Powder A and Powder B used in the experiments are spraydried WC-Co mixtures also used in previous research (Ref 7,[16][17][18]21). The average particle size for Powder A is smaller than Powder B, which typically leads to higher press forces to achieve a given relative material density.…”