The double-edge effect of second-phase particles on the recrystallization behaviour and associated mechanical properties of metallic materials

Abstract

Most industrial alloys contain a matrix phase and dispersed second-phase particles. Several thermomechanical processing (TMP) steps are usually needed to produce a final product, during which recrystallization and its related phenomena may take place. Second-phase particles may retard or accelerate recrystallization, depending on their size and spatial distribution, the TMP conditions, among others. Besides their effect on recrystallization kinetics, the introduction of second-phase particles creates additional interfaces within the matrix, it also modifies the grain structure and crystallographic texture after recrystallization, which then either improves or deteriorates the associated mechanical properties of the investigated materials. The interactions between second-phase particles and recrystallization are further complicated when these particles are not stable. In addition to particle coarsening, they can also precipitate out or dissolve into the matrix before, simultaneously with or after recrystallization. This review article attempts to summarize the recent progresses on the complex interaction between second-phase particles and recrystallization and the science behind them. This double-edge effect of second-phase particles on recrystallization behaviour and mechanical properties of metallic materials is still far from being clear. A better understanding of this issue is of high academic and industrial interests, since it provides potential freedom for TMP design and microstructure control.

Evolution of Microstructure During Double-Sided Friction Stir Welding of Microalloyed Steel

“…Pinning of subgrain and HAGBs has been shown to occur when the average particle size is in the size range 10 to 300 nm, and the particle volume fraction, f < 0.01. [64] The nucleation of particles on dislocations in the BM [15] and in both bainite in the TMAZ and ferrite in the IZ is a feature of the microstructure in the current FSW of M/A steels. EDX spectra in Figure 11 are from the particles which are more than an order of magnitude larger than the SIP seen in Figures 7, 13, and 15.…”

iCHORD-SI combination as an alternative to EDS-EBSD coupling for the characterization of γ-γ′ nickel-based superalloy microstructures

“…But many interactions between the γ grains and the γ' precipitates also occur during hot forging operations: deformation triggers recrystallization mechanisms which closely depend on the precipitation and its evolution. For instance, precipitates may dissolve to potentially reprecipitate behind the front [4,5], pin grain boundaries [6] or act as nucleation sites [7,8]. Understanding these γγ' interactions enables the optimization of the forging process so as to obtain the γ' phase distribution leading to the best mechanical properties.…”

Effect of Alumina Nanoparticles on the Microstructure, Texture, and Mechanical Properties of Ultrafine‐Grained Aluminum Processed by Accumulative Roll Bonding

“…It is well known that coarse particles generally stimulate recrystallization, while fine particles retard it. The particle size separating coarse particles from fine ones may vary but is close to ≈1 µm in many cases . In the present investigation, nanosized particles accelerate dynamic recrystallization.…”