Association EURATOM-Tekes, Department of Physics, University of Helsinki, PO Box 43, FIN-00014, Finland.
J Phys Condens Matter. 2011 Sep 7;23(35):355007. doi: 10.1088/0953-8984/23/35/355007. Epub 2011 Aug 16.
The understanding of the primary radiation damage in Fe-based alloys is of interest for the use of advanced steels in future fusion and fission reactors. In this work Fe-Cr alloys (with 5, 6.25, 10 and 15% Cr content) and Fe-Ni alloys (with 10, 40, 50 and 75% Ni content) were used as model materials for studying the features of steels from a radiation damage perspective. The effect of prolonged irradiation (neglecting diffusion), i.e. the overlapping of single 5 keV displacement cascade events, was studied by molecular dynamics simulation. Up to 200 single cascades were simulated, randomly induced in sequence in one simulation cell, to study the difference between fcc and bcc lattices, as well as initially ordered and random crystals. With increasing numbers of cascades we observed a saturation of Frenkel pairs in the bcc alloys. In fcc Fe-Ni, in contrast, we saw a continuous accumulation of defects: the growth of stacking-fault tetrahedra and a larger number of self-interstitial atom clusters were seen in contrast to bcc alloys. For all simulations the defect clusters and the short range order parameter were analysed in detail depending on the number of cascades in the crystal. We also report the modification of the repulsive part of the Fe-Ni interaction potential, which was needed to study the non-equilibrium processes.
了解铁基合金中的初级辐射损伤对于未来聚变和裂变反应堆中先进钢的使用具有重要意义。在这项工作中，使用 Fe-Cr 合金（含 5%、6.25%、10%和 15%Cr）和 Fe-Ni 合金（含 10%、40%、50%和 75%Ni）作为模型材料，从辐射损伤的角度研究钢的特性。通过分子动力学模拟研究了长时间辐照（忽略扩散），即单个 5keV 位移级联事件的重叠的影响。在一个模拟单元中，顺序随机模拟了多达 200 个单级联，以研究 fcc 和 bcc 晶格以及初始有序和随机晶体之间的差异。随着级联数量的增加，我们观察到 bcc 合金中弗伦克尔对的饱和。相比之下，在 fccFe-Ni 中，我们看到缺陷的连续积累：与 bcc 合金相比，堆垛层错四面体的生长和更多的自间隙原子簇被观察到。对于所有模拟，根据晶体中的级联数量，详细分析了缺陷簇和短程有序参数。我们还报告了 Fe-Ni 相互作用势能的排斥部分的修改，这是研究非平衡过程所必需的。
