Connection between stacking fault energy and rolling-texture type in Ni and Ni-W alloys using Schmid factor as bridge

Abstract

The possible connection mechanisms between the stacking fault energy (SFE) and rolling textures of Ni and Ni-W alloys were explored. The study comprised a systematic investigation of pure Ni, Ni-5 at.%W (Ni5W), and Ni-9 at.%W (Ni9W) alloys corresponding to combinations of a high SFE and copper-type texture, medium SFE and transition-type texture, and low SFE and brass-type texture, respectively. X-ray diffraction and electron backscatter diffraction were used to reveal the evolutions of the textures and microstructures. From the microstructure perspective, the low SFE sample tends to form a larger number of shear bands at the same strain than the high SFE sample, demonstrating that the shear bands play an important role in the formation of brass rolling textures. In addition, from the texture perspective, the low SFE samples have greater numbers of grains with high Schmid factor orientations. Samples with a high Schmid factor orientation have a stronger deformation ability than those with a low Schmid factor orientation (which dominated the low SFE sample). Moreover, grains with low Schmid factors have difficulty deforming, leading to stress concentrations around the grains and the formation of shear bands. This work can help researchers better explore the real reasons for different rolling textures.