Effect of structure and substructure on the strength of sintered zirconium carbide specimens

Effect of residual stresses on the strength of ceramic materials (Review)

“…Apart from a macroscopic heterogeneity, local changes in the composition across grains, especially in materials with a wide stoichiometry range, substan tially affect the strength of ceramic billets. A structural anisotropy and the presence of defects in a structure [9,21] cause microstresses of various kinds: micro stresses localized in regions containing individual grains or groups of grains, intergranular microstresses, microstresses spherically symmetric in grains and induced by a coefficient α gradient in the grain vol ume, and peak microstresses in the mouth of micro and submicrocracks. To estimate the local stresses in materials, researchers use various techniques.…”

“…Estimation of residual microstresses in a grain body (σ b ) and in grain boundaries (σ g ) from the broadening of X ray diffraction lines of compacted (ω c ) and milled (ω m ) powders and the fraction of intergranular fracture F cr for zirconium carbides and carbide-graphite [5] Material (2) the measurement of individual reflections from local regions in grains with an X ray microbeam [21]. Both techniques can be used to detect local stresses over wide ranges.…”