Influence of niobium solutes on the microstructural evolution of nickel during hot working

Dynamic Recrystallization Mechanisms of Nickel Niobium Alloys during Hot Working

“…Such a feature may be a clear evidence of the effect of the niobium content on strengthening by solid solution effect [11]. The influence of these initial microstructures together with the deformation parameters on the recrystallization mechanisms occurring upon deformation had been discussed recently by the authors from [12]. Evolution of Microstructural Aspects of Ni─2% wt.…”

“…This displayed topology of different grains population reflects locally heterogeneous regions in the form of variations of local crystallographic grain orientations due to strain incompatibilities between the neighbouring grains. These regions of inhomogeneity are frequently sites for the origin of recrystallization during hot working [12]. However, The development of a typical heterogeneous transition about discontinuous (DDRX) ─ continuous (CDRX) dynamic recrystallization microstructure upset at 800°C and 0.1 s -1 is clearly observed in some regions of Figure 3-a, by focusing on the recrystallized grain nucleus of alloy, the grains size completely recrystallized are much smaller than the old grains and also initial state.…”

“…In this regard, the flow behaviour constitutive equations, taking into account recovery and hardening parameters, have been already addressed by the current authors in an earlier work [11]. Then, the goal of this present work is to extend the findings of the recent work [12] to investigate and analyse the specific effect of Ni 2 and 10. %Nb on the microstructural qualitative analysis via EBSD boundary evolution maps, keeping in mind to focus attention strictly on the solute drag effect by avoiding other alloying and impurities typically present in commercial alloys.…”

“…Nb as model materials as well as the hot torsion testing procedure can be found in details elsewhere [11]. In order to analyse the mechanisms recrystallization as a function of composition and/or deformation conditions, the authors were included recently in their work [12] the metallographic conditions from the deformed and undeformed materials obtained respectively by optical and scanning electron microscopy (SEM). This latter technique SEM-based EBSD was used to determine microstructural features such as angle boundaries (LAB and HAB) and twin boundaries (TB).…”