Development of oxidation-resistant carbon fibers and evaluation of their performance in a carbon matrix composite

Here we report on a novel approach to achieve an inherent oxidation protection up to 620 degrees C in electrospun carbon fiber (CF) mats by incorporating a SiO2 precursor into a CF precursor polymer. A carbon/carbon (C/C) composite is prepared using these CF mats in a pitch-derived carbon matrix and its performance is evaluated. Oxidation resistance in CFs is achieved by a controlled addition of polydimethylsiloxane (PDMS) directly into the polyacrylonitrile (PAN) prior to electrospinning. The concentration of PDMS is optimized such that the mechanical properties of the fibers remain within the usable range. C/C composite prepared using these fibers is characterized for its thermal and mechanical properties through flame treatment and compression tests, respectively. The composite, having <0.5 wt% CFs in a carbon matrix, shows a good thermal stability and retains similar to 60 % weight at 800 degrees C in zero air atmosphere. Addition of electrospun CFs has improved its mechanical properties, which are evaluated against those of the matrix material. The prepared composite exhibits a compressive strength of similar to 68 MPa and Rockwell hardness of similar to 72 HRB. Flame treatment tests indicate a lower surface erosion and weight loss in the composite caused by a thermal shock when compared to the matrix. The fabrication method is simple, low-cost, and suitable for research applications such as device fabrication.