Ceramizable Cf/BPR composites with enhanced oxidation resistance up to 1670 °C

Ceramizable carbon fiber/boron-modified phenolic resin (C f /BPR) composites are cost-effective and suitable for fabricating large-scale components, making them vital for thermal protection systems in aerospace vehicles. However, their thermal resistance requires further improvement. This study investigates the modification of C f /BPR composites using ZrSi 2 , Al, and mica to enhance their thermal resistance. High-temperature static oxidation and oxyacetylene ablation tests are conducted to evaluate their high-temperature performance. The role of each filler on oxidation resistance is discussed. The results reveal that when ZrSi 2 is added at 33.75 phr, Al at 3.75 phr, and mica at 5 phr, the prepared composite exhibits a flexural strength of 56 MPa after 20 min of static oxidation at 1600 °C, with excellent protection of the carbon fibers. After oxidation at 1670 °C, the flexural strength remains at 45 MPa, despite some degree of carbon fiber ablation.