Initial stage sintering of polycrystalline spheres: A model and experiments

Kini, MK and Chokshi, AH (2020) Initial stage sintering of polycrystalline spheres: A model and experiments. In: Materialia, 10 (100665).

PDF MAT_10_2020.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

Conventional models for initial stage sintering consider sintering to occur between two single crystal spheres, although most powder particles are polycrystalline in reality. The conventional Coble model is modified to take into account multiple grain boundaries intersecting a neck in sintering between polycrystalline particles. The exponents N and M in the rate equation (x/R)N α (t/RM), for polycrystals were found to be 4 and 2, respectively, in contrast to 6 and 4 in single crystals; here x, R and t are the neck radius, particle radius and time, respectively. In addition there is a 1/d2 dependence, where d is the grain size. Analysis reveals that initial stage sintering will be enhanced in polycrystalline particles when the neck is large and there are a large number of grains within a particle. Accompanying experiments on close packed irregular 2D arrays of polycrystalline zirconia spheres showed that the neck growth rate was higher for the particles containing a large number of grains, compared to those with only a few grains. © 2020

Item Type:	Journal Article
Publication:	Materialia
Publisher:	Elsevier B.V.
Additional Information:	The copyright for this article belongs to Elsevier B.V.
Keywords:	DiffusionEnzyme kineticsGrain boundariesGrowth rateParticle size analysisSingle crystalsSpheresSuperconducting materialsZirconia
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	03 Nov 2021 09:17
Last Modified:	03 Nov 2021 09:17
URI:	http://eprints.iisc.ac.in/id/eprint/65158

Actions (login required)

View Item