ABSTRACT

The uniaxial flow stress of 1 μm diameter Zr-2.5%Nb micro-pillars containing a microstructure of mixed α_Zr and β_Nb phases was assessed in the non-implanted condition and after Zr⁺ implantation to simulate neutron irradiation. Zr⁺ implantation $(\overline{\psi }\approx 6dpa)$ performed at 300 °C resulted in about 20% reduction in the flow stress ${\overline{\sigma }}_{\left(ϵ=0.10\right)}$ and displayed increased serrations in the σ−ϵ response. This suggests increased thermally activated recovery of the ion-induced crystallographic defect population when irradiation damage is invoked on the αβ microstructure at 300 °C compared to at 25 °C. The αβ micro-pillars that were Zr⁺-implanted at 300 °C also display axial cracking during compression. This cracking was not observed during compression of non-implanted αβ micro-pillars nor was it observed on αβ micro-pillars that were Zr⁺ implanted at 25 °C, which illustrates the role of thermal activation during Zr⁺ ion implantation in weakening the alloy.

摘要

在非注入条件下和在 Zr ⁺注入以模拟中子辐照后，评估了 1 μm 直径 Zr-2.5%Nb 微柱的单轴流应力，该微柱包含混合的 α _Zr和 β _Nb相的微观结构。Zr ⁺注入$(\overline{\psi }\approx 6d磷\mathrm{一种})$ 在 300 °C 下进行，流动应力降低了约 20% ${\overline{\sigma }}_{\left(\epsilon =0.10\right)}$并在 σ−ϵ 响应中显示出增加的锯齿。这表明，与 25 °C 相比，在 300 °C 下对 αβ 微结构引起辐照损伤时，离子诱导晶体缺陷群的热活化恢复增加。在 300 °C 下注入Zr ⁺的 αβ 微柱在压缩过程中也显示出轴向裂纹。在压缩未注入的 αβ 微柱期间没有观察到这种裂纹，在 25°C 下注入Zr ^{+ 的}αβ 微柱上也没有观察到这种裂纹，这说明了在 Zr ⁺离子注入过程中热活化在削弱合金方面的作用.