Microstructure and microtexture evolution of dynamic recrystallization of a Ni-based superalloy under high-throughput gradient thermal compression

The GH4169 alloy with high through-put gradient distribution of strain and microstructure was obtained by thermal compression of double-frustum specimens at 1050 °C, 0.4 s−1 deformation condition. The effect of strain on the evolution of the microtexture and recrystallization of the alloy was investigated using electron backscatter diffraction (EBSD). The strain gradually increases from the edge to the center of the compressed sample, accompanied by increased recrystallization. As the strain increases, new Σ3 boundaries are generated within the dynamic recrystallization (DRX) grains, affecting the deformation microstructure in the subsequent deformation process and gradually decreasing the overall maximum intensity of the microtexture. The deformed grains are oriented in the <101> direction parallel to the compression direction (ND, equivalent to normal direction), and the orientation of the recrystallized grains is in the <001> direction with low pole density. With increasing strain, Brass and Goss of α-fiber textures characterized by {110} textures gradually weaken, and the volume fraction of the Rotated Cube increases under the effect of shear stress.