Proton Irradiation Damage of Nuclear Materials

核反应堆中使用的结构材料在服役期间经历中子辐照，了解并最终能够预测材料在服役条件下的微观结构演变是很重要的。反应堆压力容器(RPV)钢就是这样一种材料。以前的工作表明，当RPV钢暴露在辐射下时，它的断裂韧性会发生巨大的变化，变得更硬，但更脆。这在很大程度上是由于形成了各种沉淀物，包括富铜沉淀物和/或富镍锰沉淀物，这取决于合金的成分和辐射。本项目旨在研究质子辐照剂量、剂量率和温度对RPV钢组织和力学性能的影响。本项目包括以下部分：1)辐照前材料的组织和力学性能表征。2)不同剂量率、剂量和温度下的质子辐照。3)使用高分辨率STEM和EDS等先进的电子显微镜技术对辐照后的微观结构进行表征；4)辐照后的小规模力学测试，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.