Creep behavior of in situ TiCP/2618 aluminum matrix composite

The creep behavior of 2618 aluminum alloy and in situ TiCP/2618 aluminum composites (with 15% and 20% volume fraction of TiC particles, respectively) was investigated under a condition of constant compressive stress at 523, 573 and 623 K, respectively. The results showed that both the stress exponent and the apparent activation energy of the composite were higher than these of 2618 aluminum alloy, indicating that the existence of TiC particles significantly improved the high-temperature creep property of 2618 aluminum alloy. Both the calculation based on the Orowan dislocation model through the introduction of the threshold stress concept and the normalization of the creep data showed that the high-temperature creep behavior of the composites could be explained by the dislocation climb (lattice diffusion) mechanism.