Creep properties of Ir-based alloy with fcc+ L1₂ two-phase structure

The creep behavior of the Ir-Nb alloy with cuboidal L1₂ precipitates in a fee phase and the Ir-Zr alloy with a lamellar structure consisting of the fee and L1₂ phases was investigated at temperatures between 1773 and 2073 K. The stress exponent and the activation energy of the Ir-based binary alloys were estimated from the creep curves. The deformation mechanism is discussed in terms of the deformation structure observed in transmission electron microscopy, the stress exponent, and the activation energy.