Damage evolution and failure behavior of 3D needled Carbon/Carbon composites under compressive at ultra-high temperatures up to 2800 °C

In this paper, the compressive properties of 3D needled Carbon/Carbon composites at high temperatures up to 2800 degrees C were revealed from the perspective of damage evolution and fracture behavior. At ambient temperature, the results of loading-unloading and in-situ X-ray computed tomography experiments show that cracks originate from the needle-punched region on the surface when the strain threshold exceeds 0.3 %. With further loading, the material exhibits nonlinear and cumulative damage characteristics. At ultra-high temperature, the compressive strength increases first and then decreases with the increase of temperature, and reaches the maximum at 1800 degrees C. Meanwhile, the fracture mechanism of temperature control is divided into two categories. Below 2400 degrees C, the bonding of the interface improves with the increase of temperature, and the shear bands and delamination lead to catastrophic failure. At higher temperatures, the material exhibits plastic buckling, accompanied by fiber breakage, fiber kink bands, transverse cracks and delamination.