A novel promotion strategy for flexible and compressive performance of Al2O3 felt via aramid fiber composite

As high-temperature-resistant inorganic fibers, Al2O3 fibers possess high-temperature resistance, high-temperature oxidation resistance, and chemical stability, and thus are suitable for applications such as high temperature catalysis and filtration. However, their shortcomings, such as high brittleness and high fracturability, limit their applications. In this study, a flexible Al2O3/aramid composite felt was prepared by introducing aramid fibers into Al2O3 fiber filaments, and the flexibility of the prepared composite felt was improved by using needle punching. The influence of the Al2O3/aramid doping ratio on the thermal insulation performance of the composite felt was explored. The findings showed that as the Al2O3/aramid doping ratio increased, the thermal insulation performance of the composite felt improved, whereas its thermal conductivity decreased. At room temperature of 25 °C and with an Al2O3/aramid doping ratio of 12:1, the thermal conductivity of the composite felt reached its minimum value of 0.0306 W m−1 K−1, while its compression and fracture moduli became 0.4 MPa and 21.5 GPa, respectively. The thermal-insulation mechanism of the composite felt was also explored in the study.