Structure, nonlinear stress-strain state and strength of ceramic multilayered composites

摘要

The effect of structure and residual stresses on the mechanical behavior of the SiC/TiB_2 multilayer composite ceramic materials was studied. The multilayered ceramics were obtained using the following scheme: a slip casting of thin films followed by a packet rolling and hot pressing. The use of β-SiC powders allowed to obtain SiC layers with porous structure reinforced by prismatic crystals. Such structures possess the relaxation ability of thermal strains that excludes formation of cracks during material production and provides enhanced strength of the SiC/TiB_2 composite. Mechanical response of the laminated ceramic composites to static bending was studied experimentally. A procedure for solving the inverse problem using experimental data on the deformation of a laminated ceramic composite specimen in the form of a beam was developed. This approach allows the mechanical characteristics of the laminates to be predicted. The nonlinear stress-strain dependencies for the laminate as a quasi-homogeneous structure and for each of the two separate materials of the layers were obtained. The modeling of the stress-strain state of the laminate was performed.