Incorporating Metal Oxides to Significantly Improve\nthe Ablative Performance of Silicone Rubber-Based Composites at 10%\nTensile Strain Rate under Coupled Thermal-Mechanical-Oxidative Conditions

Silicone\nrubber is able to provide excellent thermal protection\nand accommodates large deformation rates. However, the ablative properties\nof silicone rubber deteriorate significantly when it is subjected\nto ablation at large strain rates. To attempt to address the above\nproblem, different types of metal oxides were adopted to enhance the\nablative properties of vinyl methyl silicone rubber (VMQ), especially\nfor enhancing the ablative performance at 10% tensile strain rate.\nThe results revealed that the combined use of iron(II, III) oxide\n(Fe<sub>3</sub>O<sub>4</sub>) and zirconium dioxide (ZrO<sub>2</sub>) was instrumental in improving the ablative properties of VMQ-based\ncomposites at 10% tensile strain rate and a heat flux of 1 MW/m<sup>2</sup>. To further enhance the ablative performance, the ratio of\nFe<sub>3</sub>O<sub>4</sub> and ZrO<sub>2</sub> was optimized through\nan experimental design method. Results showed that when the ratio\nof Fe<sub>3</sub>O<sub>4</sub> and ZrO<sub>2</sub> was 1.4:1, the\nmaximum back-face temperature of a 3 mm thick silicone rubber composite\nremained below 200 °C, while the surface temperature was well\nabove 2000 °C when it was stretched to a tensile strain rate\nof 10%. This work provides a reference for preparing high-performance\nflexible thermal ablative composites that exhibit promising application\nin aerospace and fire protection sectors, among others.