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

Our work studies the dynamic properties of coated and uncoated 2D C/SiC composite material from 173 K to 1273 K by means of Split Hopkinson Tensile Bar. Examination of the failure process of the specimen by SIM D8 ultra high-speed camera and damage analysis help define the three phases of crack propagation, namely: the elastic pre-damaged phase, the yielding phase or the crack-initiating phase, and the failure phase or the phase of fast-spreading cracks. Experimental results also reveal that the dynamic tensile strength of both coated and uncoated composites decreases with the increase of temperature and decreases more conspicuously at higher temperature. An SEM is employed to examine the fracture surface and damage of C/SiC composites at different temperatures are determined by calculation. Finally, k was introduced according to the Cowper-Symonds fitting model to describe the temperature dependency. This implies a greater significance of SiC coating on the properties of the composite with the increase of temperature. Thus, it is believed that coated composite within the temperature range of 173 K-1273 K displays a superior impact property compared with uncoated composite, and is a better structural thermal protection material. (C) 2017 Elsevier Ltd. All rights reserved.