Dependence of Intergranular Fracture Strength of a Compact of Pressed Granules on Their Deformation Characteristics

Abstract

Rumpf's equation for the tensile strength of a powder bed was modified to indicate the intergranular fracture strength of a bed of pressed granules. The cohesive force between compacted granules was assumed to be proportional to the corresponding contact area. This assumption was investigated by directly measuring the cohesive force between two granules of alumina. The contact area was estimated from a relation for the deformation of a granule under a contact force; two parameters, b and m, are used. The modified equation (Stgα Dg2(m+y)‐b‐1(1–ɛ/ɛ)1‐m–γpm+γ) predicts how the tensile strength (Stg) of a compact is affected by the compaction pressure (P), intergranular porosity (ɛ), and granule size (Dg).