Effect of second phase particles on the dynamic recrystallization in Ni-W alloys during thermal compression

Abstract The existence of second phase particles may raise the deformation heterogeneity in the alloys, providing favorable sites of recrystallization nucleation in thermal deformation. The influence of large W second phase particles (>1μm) on the dynamic recrystallization in Ni-42W alloys (with 42 wt.% W) is studied in this paper by electron backscattered diffraction (EBSD). The Ni-42W alloys are composed by NiW matrix and W particles. The W particles are of two kinds of shapes including ellipsoidal shape with a diameter of 3-10μm and rod-like shape with 3μm in width and 5-15μm in length. The phenomenon of particles stimulated nucleation is observed in the Ni-42W alloys during thermal deformation. The recrystallized grains are located not only at the areas with high-angle grain boundaries but also at the deformation heterogeneities around W particles. A divergent distribution of deformation heterogeneities is formed around the ellipsoidal W particles and the distortion degree near the adjacent ellipsoidal particles can be accumulated. Large distortion exists at the tips of the rod-like particles. The deformation is weak at the middle region between rod-like particles with parallel alignment, which is not conducive to recrystallization nucleation. Based on the EBSD results, the dynamic recrystallization evolution diagram is established for Ni-42W alloys with large second phase particles. Data Availability Statement The data that support the findings of this study are available from the corresponding author upon reasonable request.