Local Contact Compliance Relations at Compaction of Composite Powders

Abstract

Local contact behavior of composite powders has been investigated by using the finite element method. In previous analyses of such problems it has in general been assumed that one of the powder materials is rigid while the other deforms at loading as in such a case self-similarity prevails. This is a very good approximation for ceramic/metallic composites but may not be so when the composite consists of two materials of roughly equal hardness. An approximate compliance formula for describing this feature is proposed showing good agreement with corresponding finite element results for representative cases.

A numerical analysis of cold powder compaction based on micromechanical experiments

“…Recent studies of the problem with two particles in contact includes more general studies by Skrinjar et. al [10] and Olsson and Larsson [11] where elastic-plastic materials, strain hardening and adhesive eects are investigated. A sketch of a typical normal force contact relation is shown in Figure 1 and the major issue in this work is to determine this relation based on experimental results.…”

On the local contact behaviour in regular lattices of composite powders

“…However, this problem was recently investigated by Skrinjar et al [14] and approximate but accurate relations describing such contact situations were derived. The resulting formula are, however, based on theoretical considerations that can not be summarized in a brief manner and this will not be attempted here (however, the selfsimilarity relations outlined above are important constituents in the theory).…”

“…[10][11][12][13] it was shown that during packing of particles and at the first onset of loading the major densification mechanism is rearrangements of particles. In this context it should also be mentioned that in a recent study Skrinjar et al [14] derived approximate but accurate relations describing contact between dissimilar particles in a fairly general situation.…”

Critical Review on Engineering Mechanical Quality of Green Compacts using Powder Properties

“…Indentation hardness is measured by the depth of indentation when subject surface is indented by a tip with specific geometry with a pre-set force. (Skrinjar et al, 2005). In other words, it is required for an indentation tip to be much harder than subjected powder compacts with large enough dimension compared to the indentation to ensure an accurate hardness measurement, which is not always straightforward to implement especially for novel materials or materials with less known surface characteristics or mechanical properties.…”

“…Gibson et al (2015) used a finite element modeling to estimate Young's modulus and Poisson's ratio using a nanoindentation tests on micron-sized silica (SiO 2 ) particles. It should be noted that Gibson et al (2015) assumed non-slip contact, which should be further substantiated as assumptions on contact may have a significant effect especially at the microscopic scales (Briscoe and Adams, 1987;Skrinjar et al, 2005;Thornton and Ning, 1998).…”