文献类型：期刊文献

英文题名：Abnormal grain growth behavior in gradient nanostructured titanium investigated by coupled quasi-in-situ EBSD experiments and phase-field simulations

作者：Peng, Wei[1];Li, Xiao[1,2];Gao, Jiabao[3,4];He, Chenyun[1];Zhang, Yong[1];Lu, Tiwen[1];Zhang, Xiancheng[1];Zhang, Lijun[3];Sun, Binhan[1];Tu, Shantung[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Key Lab Pressure Syst & Safety, Minist Educ, Shanghai 200237, Peoples R China;[2]Huzhou Univ, Sch Engn, Huzhou 313000, Zhejiang, Peoples R China;[3]Cent South Univ, State Key Lab Powder Met, Changsha 410083, Peoples R China;[4]Huazhong Univ Sci & Technol, State Key Lab Mat Proc & Die & Mould Technol, Wuhan 430074, Peoples R China

年份：2024

卷号：276

外文期刊名：ACTA MATERIALIA

收录：;EI(收录号：20242716606711);WOS:【SCI-EXPANDED(收录号:WOS:001264416900001)】；

基金：This work was financially supported by the National Key Research and Development Project (No. 2022YFB4600019, 2023YFB3712100) , National Natural Science Foundation of China (No. 52275147, 52205152) , Natural Science Foundation of Hunan Province for Distin- guished Young Scholars (Grant No. 2021JJ10062) , New Cornerstone Science Foundation through the XPLORER PRIZE, State Key Laboratory of Long -life High Temperature Materials (DEC8300CG20221 0288EE280293) , China Postdoctoral Science Foundation (Grant No. 2023M741244) . The authors also would like to thank the MOOSE and MTEX teams for helpful advice.

语种：英文

外文关键词：Gradient nanostructured materials; Abnormal grain growth; Thermal stability; Phase -field modeling; Quasi -in -situ electron backscatter diffraction

摘要：Gradient nanostructured (GNS) metals exhibit superior mechanical properties compared with their counterparts containing a homogeneous microstructure. However, GNS materials usually suffer from the abnormal grain growth (AGG) when subjected to elevated temperatures, resulting in the instability of the gradient nanostructure and the degradation of mechanical properties. Investigating AGG and thermal stability in GNS metals is crucial for improving their high-temperature performance, but it poses significant challenges due to the inherent complexity in the GNS microstructure. In this paper, quasi-in-situ electron backscatter diffraction (EBSD) experiments and multi-order-parameter phase-field (MOP-PF) simulations are combined to perform a comprehensive study on the AGG mechanism of GNS-Ti. Both experimental and simulation results show that AGG occurs in the deformation twin enriched layer (280 mu m depth) at 700/degrees C, but not at 550/degrees C. Such difference is attributed to the larger stored energy difference between distinct microstructural layers and the faster grain boundary mobility at the higher temperature of 700/degrees C. Moreover, we reveal a dual role of deformation twins in the thermal stability of GNS-Ti. The reduced interface energy and mobility of twin boundaries contribute to an improved thermal stability of the corresponding microstructure layer of GNS-Ti. However, on the other hand, the associated change in the stored energy heterogeneity among microstructural layers may promote AGG. Based on these findings, potential microstructure strategies for enhancing the thermal stability of GNS-Ti and similar alloys are provided. It is anticipated that the presently developed approach should be suitable for understanding the thermal stability mechanisms in different GNS metals.