Predicting final stage sintering grain growth affected by porosity

TL;DR

This paper develops a modeling approach to predict grain growth during the final stage of sintering in transparent ceramics, addressing the complex transition from porosity to full density without high-pressure methods.

Contribution

It introduces a comprehensive model linking existing theoretical equations to accurately predict grain growth in the final sintering stage of MgAl2O4 spinel.

Findings

Successful prediction of grain growth transition region

Potential for pressureless transparent material production

Enhanced understanding of sintering microstructure evolution

Abstract

Grain growth has a definitive impact on the quality of transparent sintered materials in areas such as ballistics, biomaterials, jewelry, etc. Controlling the sintering trajectory at the precise moment of final stage sintering is one of the main sintering challenges for obtaining highperformance, fully-dense nano-ceramics. However, the final stage of sintering involves a very complex coupling between the rate of porosity elimination/grain growth and transition mechanisms. This complexity makes predicting the sintering trajectory very difficult, and most transparent material production escapes this problem by using expensive high-pressure methods such as hot isostatic pressing (HIP). In the quest for a pressureless transparent material process, this paper addresses the challenge of predicting grain growth in the transition domain from the grain growth onset (in a high porosity region) to full density for MgAl 2 O 4 spinel. We present a comprehensive modeling approach linking theoretical models such as Zhao \& Harmer's and Olevsky's equations to accurately predict the complex grain growth transition region of final stage sintering. This modeling approach opens up the possibility for numerical exploration of microstructure development via underlying kinetics experimental identification.