Proton Irradiation Damage of Nuclear Materials

核反应堆结构材料在使用过程中会经历中子辐照，因此了解并最终能够预测材料在使用条件下的微观结构演变是非常重要的。其中一种材料是反应堆压力容器（RPV）钢。先前的研究表明，当暴露在辐照下时，RPV钢的断裂韧性会发生巨大变化，变得更硬，但更脆。这主要是由于形成了各种沉淀，包括富铜沉淀和/或富镍锰沉淀，这取决于合金的成分和辐照。本课题旨在研究质子辐照剂量、剂量率和温度对RPV钢微观组织和最终力学性能的影响。该项目包括以下几个部分：1)辐照前材料的微观结构和力学性能表征。本文将对母合金和SMA焊缝进行研究。2)不同剂量率、剂量和温度下的质子辐照。3)利用先进的电子显微镜技术（包括高分辨率STEM和EDS）进行辐照后微观结构表征；4)辐照后小尺度力学测试，包括纳米压痕和微压缩。

Structural materials used in nuclear reactors experience neutron irradiation during service and it is important to understand and eventually to be able to predict the microstructural evolution of the materials under service conditions. One such a material is the reactor pressure vessel (RPV) steel. Previous work has shown that when exposed to irradiation, RPV steel dramatically changes its fracture toughness, becoming harder but more brittle. This was largely due to various precipitates formed including copper rich precipitates and/or nickel-manganese-rich precipitates, depending on the composition of the alloy and the irradiation. This project aims to study the effect of dose, dose rate and temperature of proton irradiation on the microstructure and resultant mechanical properties of RPV steel.The project consists of the following parts:1) Characterisation of the microstructure and mechanical properties of the materials before irradiation. Both the parent alloy and a SMA weld will be studied.2) Proton irradiation at different dose rate, dosage and temperatures.3) Post-irradiated microstructural characterisation using advanced electron microscopy techniques including high resolution STEM and EDS;4) Post-irradiation small scale mechanical testing including nanoindentation and micro-compression.