Strength characteristics of investment patterns obtained by compaction of waxy material powders in the field of centrifugal forces

The use of investment casting process is aimed at producing castings of complex configuration with increased dimensional and geometric accuracy from a wide range of casting steels and non-ferrous alloys. A number of operations during the implementation of such a process are accompanied by the appearance of defects of a thermophysical nature (shrinkage of the pattern material and its thermal expansion during melting, leading to a violation of the ceramic mold integrity), which, to a certain extent, prevents the expansion of the casting nomenclature. The formation of experimental porous investment patterns by compaction of powders of waxy materials is aimed at eliminating such defects, but, due to the lack of information on the processes accompanying the compaction of waxy powders (in some cases manifested in the elastic response of the material or a change in the strength characteristics of the compacts), requires separate study. It was previously established that the distribution of density values in a paraffin powder compact is provided by directional loading of the compacted material, including in the field of centrifugal forces, which allows obtaining the surface configuration of a body of revolution with a predictable distribution of properties in each of its sections. In this paper, using the example of forming a section of a body of revolution, a comparison is given of the calculated and experimental dependencies of the relative density of compacts (obtained from different fractions of the PS50/50 material) on the stresses arising during their compaction in the field of centrifugal forces, as well as the average values of the density of compacts on the molds rotation speed. Pictures of the stress-strain state of compacts are presented when determining the values of their compressive strength characteristic of various waxy materials. The results of the experiment are aimed at solving the problems of increasing the efficiency of processes for obtaining investment patterns, the configuration of which is a body of revolution, formed by compaction of powdered waxy materials in the field of centrifugal forces.