Effect of Texture on Cyclic-deformation Behavior of Zircaloy-4

In this paper, effect of texture on cyclic-deformation behavior of Zircaloy-4 has been investi gated. The results indicate that (1) the alloy obeys the Coffin-Manson relation ( $N_{\mathrm{f}}^\beta \Delta \varepsilon_p=C$ ), the low-cycle fatigue life in the rolling direction is higher than that in the transverse direction at a given $\Delta \varepsilon_p$, and the life difference between both directions becomes larger with lowering the $\Delta \varepsilon_{\mathrm{p}}$; (2)the alloy shows cyclicdeformation softening till fracture under low strain amplitude, showing cyclic-deformation hardening in the early stage and then cyclic-deformation softening till fracture under high strain amplitude, and the grains would rotate with the cyclic-deformation going on at a given amplitude where these grains have higher Schmid factor; (3) $\sigma_{\mathrm{s}}$ at half-life obeys the power law relation $\sigma_{\mathrm{s}}=K^s \varepsilon_p^{n^s}$, and $\sigma_{\mathrm{ib}}$ obeys the logarithmic relation $\sigma_{\mathrm{ib}}=K^b \ln \varepsilon_p+C_{\mathrm{b}}$; (4) the cyclic-deformation behavior difference in both directions stems from the texture effect. Finally, the mechanism on texture effect has been discussed in detail.