Sang Lijun, Lu Junxia, Cheng Xiaopeng, Zhang Yuefei, Zhang Ze
College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China.
School of Materials Science and Engineering, Zhejiang University, Hangzhou 310058, China.
Materials (Basel). 2025 Apr 24;18(9):1934. doi: 10.3390/ma18091934.
In order to clarify the deformation mechanism of Inconel 718 (IN718) alloy at the grain scale during tensile deformation, the deformation behaviors of IN718 alloy were investigated at 650 °C using an in situ electron backscatter diffraction (EBSD) tensile testing method. The evolution of grain morphology, crystallographic orientation, activated slip systems, grain boundaries evolution, and strain-induced misorientation were systematically analyzed during the tensile test. The results showed that the grains were elongated along the tensile direction, and the grain boundaries also became significantly curved. Meanwhile, the EBSD studies illustrated that the changes in local misorientation within individual grains were non-uniform and generally began at the grain boundaries. The low-angle grain boundaries (LAGBs) were first formed near the high-angle grain boundaries (HAGBs) and gradually expanded into the interior of the grains. The activation of the slip system and the Schmid factor were characterized and calculated based on the slip traces on the deformed grain surface. The evolution of local strain within the grains was evidenced by a kernel average misorientation (KAM) map. Finally, the plastic deformation mechanism at the grain scale was discussed in detail based on our experimental results.
为了阐明Inconel 718（IN718）合金在拉伸变形过程中晶粒尺度的变形机制，采用原位电子背散射衍射（EBSD）拉伸试验方法研究了IN718合金在650℃下的变形行为。在拉伸试验过程中，系统地分析了晶粒形态、晶体取向、激活的滑移系、晶界演变和应变诱发取向差的演变。结果表明，晶粒沿拉伸方向伸长，晶界也明显弯曲。同时，EBSD研究表明，单个晶粒内局部取向差的变化是不均匀的，且一般始于晶界。低角度晶界（LAGBs）首先在高角度晶界（HAGBs）附近形成，并逐渐扩展到晶粒内部。基于变形晶粒表面的滑移痕迹，对滑移系的激活和施密德因子进行了表征和计算。晶粒内局部应变的演变通过核平均取向差（KAM）图得到证实。最后，基于我们的实验结果详细讨论了晶粒尺度的塑性变形机制。
