Effects of particle size on inhibited grain growth

Abstract

InerL second-phase particles are often dispersed in metallic and ~c materials to control grain mo.rphology and size [1,2]. The microstructure imposed by the particles affects the final properties of the material. For Instance, diversions of particles have long been known to pin grain boundaries and inhibit grain growth [3].Many theoretical studies have examined the grain boundary pinning effect of randomly dispersed, monosized, isou'opic particles. Most of these studies are based on the Zoner approach to inhibited grain growth, in which the pinning force exerted by spherical particles on a randomly positioned grain boundary is equated with the grain boundary curvature driving force for grain growth [4]. For particle inhibited grain growth in three dimensions, the Zcner equation may be generalized as I04 INHIBITED GRAIN GROWTH Vol. 24, No. I ~ * / ~c~ J Figure 3. Computer generated pinned microstructmres for f=O.02 with various particle sizes. (a) r=2.67 Co) r---4.59 (c) r=6.22. The grain boundaries are strongly pinned by the particles, so as r increases the grain diameter increases.

Effect of particulate size of Al2O3 reinforcement on microstructure and mechanical behavior of solidification processed elemental Mg

“…However, the result of grain size measurement revealed submicron and micron size Al 2 O 3 particulates to be more effective than nano-Al 2 O 3 particulates in grain refinement. Relatively higher tendency of clustering of nanometer length scale reinforcement particulates [16] might be the plausible reason of limited grain refinement effect [17] in the case of composite with 50-nm size Al 2 O 3 .…”

Current issues in recrystallization: a review

“…For example, the kinetics of abnormal growth may well be different in 3D, which is important to the understanding of nucleation of new grains. Also, the interaction of grain boundaries with particles depends on dimensionality; in two dimensions, particles can remove curvature more efficiently than in three dimensions [124]. Recent simulation work [125] shows that low particle densities can lead to microstructural states in which an abnormally large grain can grow into a matrix of fine grains that is pinned; this happens [86]: (a) evolution of an abnormal grain with boundary mobility twice that of the matrix boundaries (v =2) and energy 40% lower (G = 0.6); (b) evolution of an abnormal grain with boundary mobility twice that of the matrix boundaries (v= 2) and energy 30% higher (G = 1.3).…”

Mg-ZrO2 Nanocomposite: Relative Effect of Reinforcement Incorporation Technique

“…large deformation process assist in homogenous distribution of reinforcement particles in matrix regardless of the size difference between the matrix and reinforcement powder [14]. However, there was an increasing tendency of clustering of the nano-ZrO 2 particles [15] with their increasing volume percentage which was more evident in the case of powder metallurgy processed nanocomposites. Reinforcement-matrix interfacial integrity was assessed in terms of interfacial debonding and nanovoids and was found to be good as anticipated for metal-oxide system [13].…”