Effects of SiC Coating and Heat Treatment on DampingBehavior of 2D and 3D C/SiC Composites

摘要

Three groups of 2D and 3D C/SiC composites were fabricated by chemical vaporhree infiltration (CVI) process process: the first group was as received received, and the second , group was treated at CDCNF1629500 °Cin vacuu vacuum atmosphere for 2h, and the third m group was deposited with a chemical chemical-vapor vapor-deposited(CVD CVD) SiC coating. Internal friction of these composites were measured by dynamical mechanicalanalysis(DMA) at different frequencies, I.e. CDCNF1629Hz, 2Hz, 5Hz, CDCNF16290Hz and 20Hz, from room temperatureto 400 °C in a air ir atmosphere. The results show that SiC coating and heat treatment decrease internalfriction of C/SiC composites and the damping peak disappears or decreases in the testing temperaturerange. The effect of CVD SiC coat he coating on damping behavior of 2D and 3D C/SiC composites is mainlying related to the change of porosity and is independent of fiber preform architecture architecture. However, the effectowever, of heat treatment on damping behavior of 2D and 3D C/SiC composites is mainly attributed to thechange in the SiC matrix and interphase bonding bonding, and it is dependent on fiber preform architecture architecture.Both of oth CVD SiC coating and heat treatment studied in this paper have no ave influence on relationshipbetween d damping amping behavior of C/SiC composites and frequency.