Improved Ceramic Manufacturability With Electric Field Assisted Sintering: Developing Underlying Principles
Abstract
High density ceramics maximize strength, translucency, thermal conductivity and provide gas tight environments. These features are key to applications ranging from armor, IR missile domes, integrated circuit substrates and solid oxide fuel cell electrolytes, respectively. To achieve desired high densities for such highly refractory materials, sintering (at times requiring hot isostatic pressing) must be performed at temperatures often in excess of 1500 deg C for extended periods of time, leading to high costs, need for specialized facilities and incompatibility with less refractory materials. While conventional densification methods utilizing high temperature and pressure have reached their limits, electric field assisted sintering has demonstrated great potential in reducing temperature constraints imposed on ceramic materials during sintering. Application of electrical fields during sintering can reduce densification temperatures from above 1300 deg C to 800 deg C, to times as short as seconds, the latter via Flash Sintering (FS). While there have been many phenomenological observations and demonstrations of Field Assisted Sintering (FAST), reliable micro and nanoscale descriptions remain lacking (1). This is not surprising given that the electrical and mass transport properties of ceramic materials differ so widely, ranging from highly insulating to metallic, from predominantly ionic to electronic conductors and all with properties highly dependent on microstructure.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 29, 2020
- Accession Number
- AD1097893
Entities
People
- Bilge Yıldız
- Harry L Tuller
Organizations
- Massachusetts Institute of Technology