Residual Stress Field of Triangular Symmetrical Composite Eutectic

Abstract

Composite ceramics by combustion synthesis under high gravity can acquire excellent static and dynamic mechanical properties. Composite ceramics were mainly composed of randomly orientated eutectics containing a triangular dispersion of orderly nano-submicrometer fibers. Our study is based on a model in which a micromechanical cell is embedded in an infinite effective medium. The micromechanical cell is composed of a fiber with eutectic interphase and matrix—atmosphere, and the mechanical property of the effective medium is same as the triangular region. This micromechanical cell is used to study residual stress field of triangular symmetrical composite eutectic. Considering fiber inclusion, eutectic interphase and matrix-atmosphere are isotropy, the residual stress distribution in the micromechanical cell is obtained. For Al2O3/ZrO2 triangular symmetrical composite eutectic, the residual stress field is evaluated quantitatively. The results show that the residual stresses increase with reducing diameter of fiber inclusion. While the diameter of fiber inclusion is bigger than 100nm, the residual stresses in matrix–atmosphere are approximately constants. The analysis result will lay a foundation for stability research of flaws in composite ceramic mainly composed of triangular symmetrical eutectic.