solid-state sintering

Solid-state sintering is a process where small particles of a material are welded together by heat, without reaching their melting point. This welding occurs through diffusion, where material moves between adjacent particles, causing them to "neck" and bond. The driving force is the reduction of surface energy as the total surface area decreases.1

This method is crucial for advanced ceramics, as it avoids the residual glassy phases found in liquid-phase sintering. This results in improved mechanical and electrical properties, especially at high temperatures. While solid-state sintering is effective, pores can become trapped within grains, making them difficult to eliminate. Sintering aids are often used to enhance the process, and pressure can be applied to further aid densification and shape formation.2