Adsorption, Diffusion, and Disconnections Leading to Grain Growth During Sintering

Abstract:  

Grain growth during sintering is conventionally described as curvature-driven grain boundary (GB) motion governed by GB energy and mobility. However, recent experiments show that local curvature alone cannot reliably predict the direction or velocity of GB migration in crystalline materials. Unlike soap bubbles, crystals have atomistically structured, crystallographically anisotropic interfaces. This lecture presents grain growth as a defect-mediated process, focusing on how dopant adsorption, charge-compensating defects, and GB complexions affect disconnections; the linear defects that facilitate GB migration.

Bio:

Prof. Kaplan focuses his research on the structure, chemistry, and energy of interfaces: primarily between metals and ceramics. Applications include the development of ultra high temperature ceramics for use in aerospace applications, metal-ceramic composites for the development of jet engines and automobile brake pads, as well as flash memory devices, and in defense applications. His research in materials science makes use of the Technion’s high resolution transmission electron microscope, housed in the Electron Microscopy Center, to understand how the type and position of atoms at metal-ceramic interfaces influence properties of materials.