Numeric modeling of the strength and longevity of structures with allowance for scale effect. Report 2. Investigation of the strength and longevity of hard-alloy dies for high-pressure apparatus

Abstract

The results of evaluation of the structural strength and longevity of a hard-alloy die of anvil-type high-pressure apparatus (HPA) with recesses intended for the synthesis of superhard materials are presented. Calculations are performed by the finite-element method (FEM) with allowance for the characteristic features of content interaction and the thermoelastoplastic stress-strain state of the basis HPA components, as well as the structural inhomogeneity of the material, which is sensitive to scale effect. Isolines of equivalent stresses in the die in accordance with the Pisarenko-Lebedev strength criterion after assembly of the HPA and in its loading regime with the effective pressure and temperature are obtained. The number of load cycles required to fail the die is established using the developed longevity criterion. The dependence of the strength and operational stability of geometrically similar dies on their effective volume, which agrees satisfactorily with experimental data, is investigated.