Positron annihilation study of vacancy-solute complex evolution in Fe-based alloys
Positron annihilation study of vacancy-solute complex evolution in Fe-based alloys
复制标题
DOI：
10.1103/physrevb.67.224202
复制
发表时间：
2003-06-11
影响因子：
3.7
通讯作者：
Hasegawa, M
中科院分区：
文献类型：
--
作者：
Nagai, Y;Takadate, K;Hasegawa, M
用正电子湮没方法、正电子寿命和正电子湮没辐射的符合多普勒展宽（CDB）研究了核反应堆压力容器钢的模型合金Fe基稀二元合金（Fe-C、Fe-Si、Fe-P、Fe-Mn、Fe-Ni和Fe-Cu）中辐照诱发的空位型缺陷。在室温下用3 MeV电子辐照产生空位型缺陷。缺陷浓度远高于在相同条件下辐照的纯Fe中的缺陷浓度，表明空位与溶质原子之间的强烈相互作用以及空位-溶质复合物的形成。CDB技术明确地识别了Fe-Cu、Fe-Ni和Fe-C合金中的空位溶质络合物。特别是Fe-Cu中的单空位被Cu原子包围，形成V-Cu-n（n ≥ 6）空位-多Cu原子复合物。在Fe-Ni和Fe-P合金中形成空位团簇，而在其它合金中未观察到空位团簇。研究了等时退火行为。在350 ℃退火后，在Fe-Cu中形成与Fe基体共格的超细Cu沉淀物，而其他合金显示完全恢复，而没有形成任何捕获正电子的沉淀物。
Irradiation-induced vacancy-type defects in Fe-based dilute binary alloys (Fe-C, Fe-Si, Fe-P, Fe-Mn, Fe-Ni, and Fe-Cu), model alloys of nuclear reactor pressure vessel steels, are studied by positron annihilation methods, positron lifetime, and coincidence Doppler broadening (CDB) of positron annihilation radiation. The vacancy-type defects were induced by 3 MeV electron irradiation at room temperature. The defect concentrations are much higher than that in pure Fe irradiated in the same condition, indicating strong interactions between the vacancies and the solute atoms and the formation of vacancy-solute complexes. The vacancy-solute complexes in the Fe-Cu, Fe-Ni, and Fe-C alloys are definitely identified by the CDB technique. In particular, the single vacancies in Fe-Cu are surrounded by Cu atoms, resulting in vacancy-multi-Cu-atom complexes of V-Cu-n (ngreater than or equal to6). The vacancy clusters are formed in Fe-Ni and Fe-P, while they are not observed in the other alloys. The isochronal annealing behavior is also studied. The ultrafine Cu precipitates coherent with the Fe matrix are formed in Fe-Cu after annealing at 350 degreesC, while the other alloys show complete recovery without forming any precipitate that traps the positrons.