【作者】 刘廷光； 夏爽； 李慧； 周邦新； 陈文觉； 白琴；

【Author】 LIU Ting-guang;XIA Shuang;LI Hui;ZHOU Bang-xin;CHEN Wen-jue;BAI Qin;Institute of Materials,Shanghai University;Key Laboratory for Microstructures,Shanghai University;

【机构】 上海大学材料研究所； 上海大学微结构重点实验室；

【摘要】 本文对不同晶粒尺寸的690合金样品进行晶界工程处理,利用电子背散射衍射和取向成像显微技术分析了晶界工程(GBE)处理中部分再结晶状态和GBE处理后样品的晶界网络。结果显示,以小形变量冷加工及高温短时间退火为特征的GBE处理是"低应变-再结晶"过程,再结晶晶核长大过程中发生多重孪晶,构成晶粒团簇显微组织。原始晶粒尺寸对GBE处理后样品的晶界网络有显著影响,不同原始晶粒尺寸的样品经过合适工艺GBE处理后,低∑CSL晶界比例都能提高到70%以上,但是不同原始晶粒尺寸样品的最佳GBE处理工艺不同。要想获得更高比例的低∑CSL晶界(80%以上),需要适中的原始晶粒尺寸和合适的GBE处理工艺。更多还原

【Abstract】 Effects of initial grain size on the evolution of grain boundary network(GBN) during grain boundary engineering(GBE) of Alloy 690 were studied using electron backscatter diffraction and orientation imaging microscopy technique(EBSD-OIM) in this work.Microstructures of the partiallyrecrystallized samples revealed that GBE-processing is a strain-recrystallization process,during which each grain-cluster was formed by "multiple-twinning" starting from a single recrystallization nucleus.Initial grain size has important effects on the GBN after GBE processing.GBE can increase the low-Σ CSL grain boundary proportion to more than 70%regardless of initial grain size.However,the suitable GBE procedure is different to samples with different initial grain size.Suitable initial grain and proper GBE processing combination is needed to form optimized GBN with high proportion of low-ΣCSL boundary(>80%).更多还原