Understanding the creep behavior of a 2.5D Cf–SiC composite: II. Experimental specifications and macroscopic mechanical creep responses

Macroscopic results for a 2.5D Cf–SiC composite creep tested in tension are presented. After the development and the optimization of a new accurate high temperature tensile device, tests were conducted in argon, under a reduced pressure, for stresses ranging from 110 to 220 MPa and temperatures between 1273 and 1673 K. The macroscopic mechanical creep responses of the composite were analyzed and interpreted. Since ceramic matrix composites (CMCs) contain constituents of a different nature, with an influence of a structural aspect, it is not possible to apply the hypotheses of homogeneity and isotropy as described in Dorn’s theory. Consequently, the physical meaning of the mechanical parameters, obtained by such a classical treatment, is limited. It is then necessary to discuss the global creep responses using an approach based on damage mechanics, which is more consistent with the specific features of the CMCs. This new approach adopted here reveals less classical parameters to be more accurate indicators of the creep behavior and the strain mechanisms of the 2.5D Cf–SiC composite.