Abstract
The effect of an H-field or E-field on the sintering and decrystallization of titanium oxides during 2.45 GHz microwave heating was investigated. Titanium oxides (TiO2-x) were heated in a TE103 single-mode cavity, which was used to separate the maximum point of the H-field or E-field of the 2.45 GHz microwave radiation. Scanning electron microscopy (SEM) images taken after H-field heating showed that the sample was sintered well above 1400 °C. In the X-ray diffraction (XRD) patterns, the intensity of the diffraction peaks of TiO2 decreased with increasing heating temperature between 1200°C and 1400 °C. After heating at 1500°C, however, the TiO2 peak intensities increased and undefined peaks emerged. Decrystallization is the dominant reaction, driven by the nonthermal microwave effect, below 1400°C. As the effect of the thermal energy becomes larger than the nonthermal microwave effect above 1500°C, grain growth becomes the dominant reaction. During E-field heating, the surface structure changes to fiber-like and dot-like structures, while some areas are oxidized by plasma excited by the microwaves.
Original language | English |
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Pages (from-to) | 553-556 |
Number of pages | 4 |
Journal | Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy |
Volume | 59 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2012 Sep |
Keywords
- Decrystallization
- Microwave H-field sintering
- Sintering temperature
- Sintering theory
- Titanium oxides
ASJC Scopus subject areas
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Metals and Alloys
- Materials Chemistry