Prediction For Thermal Conductivity Of Ceramic Matrix Composites Based On XCT Technology And Application

Ceramic matrix composites(CMCs) with high low density, good high temperature resistance,made it widely used in aero-engine. Thermal conductivity is one of the important physical parameters of the mechanical CMCs, also it is the basic parameters of CMCs which is required for thermal analysis. Because the microstructure of CMCs is complex and thermal conductivity appears to be anisotropic, it is difficult to predict the thermal conductivity and it is an urgent problem to be solved in engineering application.A new method based on X-ray computed tomography(XCT) and image recognition technology has been developed to achieve the identification of component of 2.5D CMCs with self-developed program and reconstruction of micro-geometrical model of 2.5D CMCs. Based on the identification of the component, finite element model has been converted from geometrical model based on APDL language program. Micromechanical finite element method is adopted to predict the thermal conductivity of CMCs. Measurement of thermal conductivities is conducted based on hot disk thermal constant analyzer and calculated results coincide with test results well.Finally, a new engine exhaust nozzle flap has been redesigned with ceramic matrix composites and its temperature distribution under certain boundary conditions has also been calculated with the predicted thermal conductivities.