Abstract
In presented paper, cold plastic deforming of porous powder metal materials is considered not only as a changes in shape product technological operation, but also as a process that shapes the material itself, its structure, and properties. The paper examines the physicochemical aspects of the influence of external force factors on the processes of interparticle contact formation in a powder medium. The activation of the contact surfaces of metal particles is analyzed using copper powder as an example, during the formation of products from materials based on it during cold plastic deforming processes. As a result of the completed research, analytical dependencies were proposed and graphs were constructed reflecting the patterns of formation of active centers on the contact surfaces of deformed copper powder particles. Using the obtained dependencies, it is also possible to predict the strength properties of the resulting discrete materials depending on the degree of deformation and the parameters of pressure microwelding during their production. It was established that an increase in the strength of a powder material can occur not only as a result of its compaction and hardening of the base material itself, but also as a result of the phenomenon of solid-phase microwelding, i.e. The presence and realization of active centers at the actual contact spots of powder particles. The presented results can be useful and recommended for analyzing the interaction processes of powder particles during pressure processing of non-compact powder metal materials.
Keywords:
powder material, cold plastic deformation, activation of contact surfaces, active center, dislocation exit on contact surface frequency, dislocation density, dislocation exit on contact surface energy, relative strength