Goal: Formulation of empiric formula, which establishes relations between major matrix parameters of ceramic materials and composites and the coefficient of resistance to material thermogradient. Method: Harcpurt’s method of cooling of water in boiling regime till disappearance of water. Results: It is proved that work-pieces reveal maximum thermal resistance and preservation of exploitation properties, when total closed porosity is within 2% - 8%, and pore sizes vary within 1 - 6 mcm. Besides, they are more or less of spherical form and are spread equally in the matrix. Conclusion: Thermogradient effect formula was defined for complex form work-pieces, when surfaces in the pieces are transacted several times by angles of various curvature radii.
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