Mechanical Behavior of 2D C/SiC Composites at Elevated Temperatures under Uniaxial Compression

Abstract

As Carbon-fiber-reinforced SiC-matrix (C/SiC) composites are widely used in high-temperature structural applications, its mechanical behavior at high temperature is important for the reliability of structures. In this paper, mechanical behavior of a kind of 2D C/SiC composite was investigated at temperatures ranging from room temperature (20C) to 600C under quasi-static and dynamic uniaxial compression. The results show the composite has excellent high temperature mechanical properties at the tested temperature range. Catastrophic brittle failure is not observed for the specimens tested at different strain rates. The compressive strength of the composite deceases only 10% at 600C if compared with that at room temperature. It is proposed that the decrease of compressive strength of the 2D C/SiC composite at high temperature is influenced mainly by release of thermal residual stresses in the reinforced carbon fiber and silicon carbon matrix and oxidation of the composite in high temperature atmosphere.

An investigation of dynamic failure progress and properties of 2D C/SiC composite from 173 K to 1273 K by SHTB

“…From which it can be seen that D basically equals zero when the stress is less than 80MPa and the composite is in the first segment of elasticity, thus no damage can be observed from the figure 5 (a)-(c); later when the stress value increases from 80MPa to 150MPa and enters the second stage of yielding, the composite is being damaged with a very small damage (D less than 0.1), thus small cracks and regional fiber yielding can be observed on the surface of the specimen ( due to the influence of temperature elevation on the dynamic tensile property of 2D C/SiC composites [27]. At 173K, the tensile strength reaches maximum value of 335MPa and 307MPa for coated and uncoated specimen, up by 18% and 15% than that of 293K, and slightly lower in failure strain than that of 293K.…”

“…Labrugere [24,25] et al studied the dynamic tensile properties of the material at 1100-1300 which turned out to be supreme. Li et al [26][27][28] systematically investigated into the dynamic compressive properties of C/SiC material at strain rates ranging from quasi-static to 10 3 /s and temperatures ranging from room temperature to 1273K. The results showed that the material is strain-rate sensitive with the dynamic compressive strength decreased with the increase of rise of temperature.…”

Compression damage identification of stitched 2D-C/SiC based on acoustic emission pattern recognition

“…Compared with CVI and LSI, PIP has many advantages such as lower component fabrication time to reduce costs significantly and lower fabrication temperature [6,7]. Compression is an important load state of C/SiC materials in service [8,9]. Moreover, the C/SiC components will fail due to the compression damage even when the components are loaded in tension [10].…”