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In the present work, a method for modelling of processes, which are taking place in obtaining and use of compacted powder metal-composites, were built up. The models of the main steps of powder compaction were considered, i.e., compaction, relief and relaxation processes, elastic properties of a press-tool, the contact interaction of the compacted powder metal-composite with the press-tool, and the metal-composite visco-plastic properties. The model of deformation of compacted powder metal-composite under the ambient action (higher humidity, temperature, etc.) was developed. The models were built up for the processes that take place on the structural elements of compacted powder metal-composites based on nano-powders under static and dynamic loading. For this purpose, the methods of molecular dynamics, mesodynamics and continuum mechanics were used depending on the structural level that was modelled.
Based on the models built, numerical schemes, algorithms and programs were developed for the analysis of evolution processes in powder systems during powder obtaining, their compacting and the use of metal-composites
The numerical modelling based on the models developed was carried out. Various regularities of the above processes were investigated. The calculations were carried out using Verlet scheme, Runge-Kutta method and the finite element method.
Numerical investigations of the evolution of residual stresses in powder composites under compaction were carried out. The influence of the contact between powder mixture and a press-tool, external friction, powder properties, the size and the form of an item produced on the level and distribution of internal stresses was investigated. This allowed determining the regularities of powder compaction and the unloading and relaxation processes in powders and establishing reasons for possible item failure at any stage of its production.
The results of modelling and numerical analysis were used for the development of new equipment and procedures that allowed decreasing the level of residual stresses, increasing the homogeneity of compaction and increasing the strength of composites.
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