Deformation of Interparticle Necks by Diffusion‐Controlled Creep

Abstract

The deformation of a neck between two spherical particles of the same size by coupled grain‐boundary and surface diffusion has been simulated numerically through the finite‐difference method. In the case of pure sintering where there is no applied stress, the results agree quite well with simple analytical models. When a force is applied, it is found that they do not deform as truncated spheres, even when surface diffusion is much faster than grain‐boundary diffusion. Expressions are given representing the rate of approach of the particles and the rate of growth of the neck as a function of the current neck radius and the applied stress.

Factors influencing particle agglomeration during solid-state sintering

“…du/dt is the tangential component of relative velocity at the contact and η is the viscous parameter. Equation (2) consists of grain boundary diffusion and surface diffusion, which is originally and strictly obtained by Bouvard and McMeeking [35] and Parhami and McMeeking [29] from the physics and mechanics view-points. The first term on the right hand side of Eq.…”

A three-dimensional dual-mechanism model of pore stability in a sintering alumina structure

“…Here, x is the diameter of the narrowest part of the neck, and a is the original grain diameter. The simulation by Bouvard and McMeeking [9] was verified against the theoretical model presented by Coblenz et al [10] whose expression for early stage neck growth is,…”

“…(8) is an improvement on the method employed by Bouvard and McMeeking [9], which was based on a ring volume calculated in a plane normal to the rz-plane. This was verified when the sum of the volume changes over all the elements was determined.…”

“…3) which is relevant to curvature calculations was also calculated locally with the 2 P i spline. Considering the surface in spherical coordinates, the two principal radii of curvature, K a and K b can be calculated from φ as [9],…”

Application of the complex network method in solid-state sintering

“…In granular compacts, particles contact and interact with their neighbors and all contacts among neighboring particles constitute a complex contact network. During sintering, contact particles in compacts fuse with each other by a special force with the underlying mechanisms of grain boundary diffusion and surface diffusion [2]. Interacting forces are transmitted through the inter-particle contacts and the magnitudes vary significantly at different regions due to the different contact configurations, which lead to a complex force network accompanying with the contact network.…”