Fracture mechanism of a fracture-resistant CNT/alumina nanocomposite at cryogenic temperature

Abstract The fracture behavior of a carbon nanotube (CNT)/alumina nanocomposite at cryogenic temperature (77 K) is reported. The hardness and fracture toughness of the composite at 77 K increase 64.8% and 22.7% , respectively, over that at 293 K. The effect of the interfacial bonding strength between CNTs and alumina grains on the fracture mode and consequently on fracture toughness at 77 K has been studied by fractographic analysis. In addition, the mechanism of fracture toughness enhancement of the nanocomposite at cryogenic temperature is theoretically analyzed.