Interfacial-Liquid-Activated and Electrically-Driven Ultrafast Sintering and Far-From-Equilibrium Microstructural Evolution
Abstract
This three-year project has investigated field-assisted and interfacial-liquid-activated materials processing, including ultrafast sintering and far-from-equilibrium microstructural evolution. First, the mechanistic understandings of flash sintering uncovered in our earlier AFOSR-supported work enabled the development of general ultrafast sintering methods without electric fields in specimens in collaborative studies acknowledged this grant. Furthermore, we demonstrated that flash sintering can alternatively be activated by a liquid-like interfacial phase in Bi2O3-doped ZnO and an electric field can induce far-from-equilibrium microstructural evolution. Notably, we combined advanced microscopy with first-principles modeling to discover an electrochemically induced grain boundary disorder-order transition in Bi2O3-doped ZnO, which can subsequently enhance grain growth. This discovery has enriched and advanced our fundamental knowledge in grain boundary phase-like (complexion) transitions and electric field effects on microstructural evolution, and built a bridge between these two important scientific fields. In addition, we have investigated a series of ZnO-Bi2O3 based systems. Here, another new discovery is represented by the field-induced migration of the Bi-rich liquid and interfacial liquid. The interplay of an applied electric field and a liquid-like interfacial phase led to intriguing and interesting microstructural evolution phenomena. Furthermore, we investigated electric-field assisted and interfacial-liquid-activated microstructural evolution in ZnO specimens co-doped with Bi2O3 and Pr6O11, Sb2O3, Sb2O3 or TiO2, as well as ZnO specimens annealed in water vapor with applied fields. Finally, we have conducted a preliminary study to show that an electric field can be used to create graded microstructures in ZnO. We also made contributions in several other related fields.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 14, 2023
- Accession Number
- AD1231201
Entities
People
- Jian Luo
Organizations
- University of California, San Diego