High-strength prestressed composite ceramic and preparation method thereof

Abstract

The present invention discloses a high-strength prestressed composite ceramic and a preparation method thereof, and belongs to a ceramic reinforcing technology in the field of high-performance structural ceramics. Firstly, more than two kinds of bondable ceramics need to be determined to form a composite ceramic of a matrix material and a surface layer material, the matrix material should have sufficient strength and a higher expansion coefficient, and the surface layer material should have a lower expansion coefficient and a higher elastic modulus, realizing the balance of the surface layer compressive stress and the matrix tensile stress are formed after high-temperature co-sintering; and the surface layer compressive stress can greatly improve the bending strength of the composite ceramic. The magnitude of the compressive stress can be adjusted by optimizing the section ratio of the two materials of the cross sections, the surface prestress is designed to be more than the strength value of the surface layer material for the given two materials, and the section ratio is determined through deduction and calculation of a prestress calculation formula. The composite ceramic with prestress can be obtained after sintering greatly improving the strength. The present invention solves the current problem of difficulty in improving the strength of structural ceramics and has good practical value.