Characterization of carbon fiber-reinforced ultra-high temperature ceramic matrix composites fabricated via Zr-Ti alloy melt infiltration

Carbon fiber-reinforced ultra-high temperature ceramic matrix composites (C/UHTCMCs) were fabricated via Zr-Ti alloy melt infiltration (Zr-Ti MI) using carbon-carbon composite (C/C) preforms and alloys with three different compositions. Alloys were successfully infiltrated into C/C to form solid solutions of TiC and ZrC, with melting temperatures > 2900 °C. Notably, residual alloys were not observed after MI occurred at 1750 °C. Bending strength and fracture toughness of the C/UHTCMCs at room temperature and 1500 °C in air/Ar revealed that mechanical properties of the composites were similar to those of the C/C preform. During arc wind tunnel tests at 2000 °C, a recession of C/UHTCMCs fabricated using Ti-rich alloys was observed; however, this behavior was not observed for the composites prepared using Zr-rich alloys owing to the formation of a ZrO2 solid solution. Accordingly, Zr-Ti MI is a viable method for preparing C/UHTCMCs without degrading the mechanical properties of the C/C preform, while increasing the ablation resistance.