This work revealed the origin of the anisotropic ductility and the dynamic recrystallization-like deformation behavior at elevated temperature of laser powder bed fusion (LPBF) processed Inconel 625. Specimens along horizontal (HOR) and vertical (VER) directions with respect to the build platform were built. Rotation of elongated grains was evidenced by the movement of its low angle rotation axes from <001> towards <112> along <001> ∼ <111> line during deformation. Consequently, geometric hardening and softening accompanied with grain rotation was responsible for the dynamic recrystallization-like flow stress fluctuation during deformation. Moreover, variation of the rotation axes between grains is observed in the HOR specimen, suggesting that the occurrence of compatible deformation between grains is needed. However, intergranular cracks were observed in the HOR specimen, demonstrating grain boundaries embrittlement. Hence, the decrease of ductility of the HOR specimen is originated from incompatible grain deformation when deformation was perpendicular to grain boundaries.

这项工作揭示了激光粉末床熔融 (LPBF) 加工的 Inconel 625 在高温下各向异性延展性和动态再结晶样变形行为的起源。相对于构建平台沿水平 (HOR) 和垂直 (VER) 方向的试样建造了。细长晶粒的旋转通过其低角度旋转轴在变形过程中沿 <001> ~ <111> 线从 <001> 向 <112> 的移动来证明。因此，伴随晶粒旋转的几何硬化和软化是变形过程中动态再结晶状流动应力波动的原因。此外，在 HOR 试样中观察到晶粒间旋转轴的变化，表明晶粒间需要发生相容变形。然而，在 HOR 试样中观察到晶间裂纹，表明晶界脆化。因此，当变形垂直于晶界时，HOR 试样的延展性下降是由于不相容的晶粒变形所致。