The effect of liquid phase chemistry on the densification and strength of cold sintered ZnO

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Authors

External Organisational units

  • Department of Materials Science and Engineering, The Pennsylvania State University

Abstract

Cold sintering is a chemo-mechanical densification process which allows densification of ceramics at low temperatures below 300 °C. This substantial reduction in the sintering temperature is enabled by an externally applied pressure and a compatible transient liquid phase. In this paper, ZnO is cold sintered using various commercial organic acids: formic, acetic and citric acid. The effect of these different transient phases on densification, microstructural evolution and mechanical response is investigated. Fourier transform infrared spectroscopy, thermogravimetric analyses and transmission electron microscopy were conducted to explain the chemical interactions in the cold sintering process. High relative densities (∼ 96 %) were achieved by formic and acetic acid, whereas poor densification was obtained for citric acid (< 80 %), despite the higher expected solubility of zinc oxide. The higher biaxial strength found in samples sintered with formic acid compared to acetic acid (i.e. ∼90 MPa vs. ∼40 MPa) is discussed supported by fractographic analyses.

Details

Original languageEnglish
Pages (from-to)1531-1541
Number of pages11
JournalJournal of the European Ceramic Society
Volume43.2023
Issue number4
DOIs
Publication statusPublished - 2023