Effect of novel aluminium titanate on mechanical, thermal and ablation performance behavior of carbon fiber reinforced phenolic resin composites

Abstract Thermal Protection Systems (TPS) protect re‐entry space vehicles from the harsh heating they encounter when hypersonically flying through a planet or the earth's atmosphere. Carbon fiber‐reinforced phenolic resin composites were widely used for the thermal barrier structure of aerospace re‐entry vehicles. A Novel Aluminium Titanate (Al 2 TiO 5 /AT) micro powder‐modified Polyacrylonitrile (PAN) based Carbon Fiber Fabric‐Resorcinol Phenol Formaldehyde Resin (C‐PR) (AT‐C‐PR) composites are well prepared to meet the requirements of TPS. The AT may act as an insulating layer and anti‐ablative material due to its excellent thermal shock resistance in TPS. To understand the effectiveness of AT content on density, barcol hardness, interfacial interactions, thermal conductivity, and thermal stability, the C‐PR composites were produced with and without loading of AT with various weight percentages, namely 0 wt% (C‐PR), 1,3, and 5 wt% (AT‐C‐PR) by hot compression molding method. The microstructural and elemental change of the composites were analyzed by microscopic and spectroscopic studies. Results suggested that the Interlaminar Shear Strength (ILSS) of the composites was increased by about 14% at 1 wt% of AT loading. Mass, Linear Ablation Rates (MAR, LAR), and back‐face temperature of C‐PR and AT‐C‐PR composites were decreased to 0.15128 g/s, 0.01233 mm/s, and 405°C, respectively by loading of AT up to 1 wt%. The thermally ablated composites were also evaluated for their crystallographic phase changes. The work provided an effective way to improve the thermo‐mechanical and ablation performance characteristics of the AT‐C‐PR composites that can be potentially used in TPS of re‐entry vehicles. Highlights This investigation utilized innovative Al 2 TiO 5 /Aluminium Titanate (AT) ceramic powder as a filler in reinforcing Phenolic Resin (PR) with PAN‐based Carbon Fiber (C). It examined the impact of various loadings of AT in C‐PR composites (AT‐C‐PR) on their physical, mechanical, thermal, and anti‐ablation properties. The AT‐C‐PR composites exhibit reduced density, lower thermal conductivity, and enhanced ILSS (31 MPa) compared to the C‐PR composites. Optimal ablation resistance and thermal stability were achieved with a loading of 1 wt% AT (Mass Ablation Rate: 0.15128 g/s and Linear Ablation Rate: 0.01233 mm/s) compared to the C‐PR composites. Microstructural and elemental analysis of the composites were conducted using microscopy and energy‐dispersive spectroscopy, revealing the presence of oxides and carbides on the ablated surface. The phase transition and alterations in microstructure, coupled with the oxidation of AT, have enhanced the ablation resistance and reduced the back face temperature of different weight percentages of AT‐C‐PR composites, such as 1 wt% AT (413°C), compared to the C‐PR composites (704°C).