Equal channel angular pressing (ECAP) works as a useful method for microstructure refinement and strength hardening. Billets of the as‐cast and solution‐treated Mg–Gd–Nd–Zn–Zr alloy are processed by ECAP to investigate influence of pre‐solution treatment on the microstructure and mechanical properties of the alloy. The average grain size is refined from 80 to 1.5 µm after eight passes at 375 °C. Both yield stress and ultimate tensile strength of the alloy in two conditions are improved after multi‐pass ECAP. The retained broken eutectics as well as precipitation produced during ECAP may provide a stronger strength. Compared to the as‐cast alloy, solution‐treated alloy possesses higher elongation after ECAP. The variation in strength and ductility can be explained by the texture modification and microstructure evolution.

Because of the temperature effect of the distributed strain observation, it is not easy to analyze the real strain in tested data. Experiments of fibers under different temperatures and force conditions are carried out. The bare fiber, Φ 0.9 SM and Φ 2.0 SM single-mode sleeve fibers are chosen in the experiment scheme. It was found that the temperature effect of the distributed strain is independent with the force condition. The additional strain of fibers under the stress and different temperatures are discussed. For practices using, temperature correction equations on single-mode sleeve fiber are proposed to reduce the temperature effect.