Model of plastic deformation of powder materials taking account of the proportion of contact volume

A structural model is suggested that takes account of the contact nature of plastic deformation of a powder body. It is shown that in averaging local stresses and strain rates the volume of averaging can be presented as a combination of straight cylinders constructed at all contact areas of a particle and having a common nucleus formed by the intersection of cylindrical bodies. On the whole a plastically deformed powder body is an orientated contact-rod system composed of cylinders that are in contact by their bases and that experience uniform tension-compression deformation. The volume fraction of powder body contact volume determined using Bal'shin's and Zhdanovich's equations can be a quantitative measure of the volume fraction of plastically deformed material. The contact-rod model satisfies boundary conditions for the poured state of powder and it is good agreement with experimental data for isostatically compacted metal powders.