The correlation of technological parameters and the structure of cold sintered iron as a basis for material property prognosis

This study researches the influence of microstructure formation on the technological parameters of cold sintered iron powder. The emphasis is given to the study of the material characteristics structure in consideration of the crystal structure, grain size and evolution of the microstructure constituents. From the thermodynamic point of view, the problem of microstructure stability was studied in particular. The correlation of characteristics of cold sintered material and structure is illustrated, keeping in mind the mechanism and kinetics of the consolidation process, deformation problems of powder particles when being pressed and the conditions of grid defect reproduction. In order to achieve this research, a high pressure device was made according to our own original design for the consolidation of material. This device was made in such a way that it is able to change the conditions of the material consolidation by changing the pressure of pressing up to 20 GPa which by the use of special inserts made of composite material based on epoxy resin and glass fibers enable isostatic pressing. The device registered the behavior of iron powder during pressing within the range of 4.5–12.5 GPa.The resulted pressings were subject to the following testing: microstructural (light and scanning microscopy, and microhardness testing), electrical (specific electrical resistance, thermal electromotor force) and magnetic characteristics (coercive field intensity of magnetization). Also, testing by the differential thermal analysis (DTA). Research of certain phenomenons and processes that characterize material consolidation by cold sintering, explanation of their dependence on the material structure was conducted in the aim of creating conditions for synthesis of new materials and products with previously assigned properties.