Strengthening of 2D-C/SiC composite through creep with low stress and high temperature

摘要

To improve the resistance to matrix cracking of 2D-C/SiC composite, the composite was treated at certain creep conditions, which involve relative lower stress, higher temperature. The creep strain and matrix cracking stress (σ_(mc)) were used to determine the creep strengthening effect. Moreover, the stress redistribution model was applied to explain the stress transfer from the matrix to fibre, and therefore the creep strengthening mechanisms. The results indicate that 2D-C/SiC can be strengthened by creep at certain conditions. The ability to resist the creep strain and σ_(mc) can be improved by certain creep treatments with creep temperature of 1400°C, lower stress and longer time. The strengthening effect is resulted from the stress redistribution during the creep. The tensile residual stress is relaxed in the matrix and transferred to the fibre. The stress redistribution leads to compressive stress in the matrix and takes the advantage of superior creep resistance of carbon fibres.