Effect of loading rate and temperature on monotonic tensile behavior in two-dimensional C/SiC composites

The effect of loading rate and temperature on the monotonic tensile behavior of a 2D C/SiC composite was investigated. C/SiC composites with the same area were fabricated by a chemical vapor infiltration and then some were heat-treated (HT) at 1500 °C and 1900 °C in argon, respectively. The dog-bone shape specimens were machined and subjected to a monotonic tensile test. The results showed that when the loading rate was within 0.0002-0.01 mm/s, the strength changed slightly. The failure mode exhibited a transition from brittle to a tough fracture when the loading rate was decreased. The elastic modulus of the as-received, 1500, and 1900 °C HT specimens increased by 17.6, 23.1, and 5%, respectively with the rise in loading rate. After HT, the strength and the modulus decreased whereas the work of fracture began to increase, indicating excellent fracture toughness.