Plasticity Theory for Porous Metals and its Application

Abstract

The theory, already proposed by the authors, is modified. A constant stress-strain curve is obtained for the matrix metal from simple compression of sintered copper with different density ratios.
From the theory the relationship between the density ratio and compressive strain is obtained for the case of simple compression and compared with the experimental results for sintered copper.
By introducing the concept of a reduced pressure, that is, tool pressure divided by instantaneous flow stress, it is possible to develop a generalised curve of density ratio versus reduced pressure which may have some general applicability to closed die compression of sintered metals. This curve is utilized to obtain a relationship between density ratio and tool pressure, being compared with the experimental results for sintered copper.