Non-thermal Microwave Effects Result in Melting Point Reduction
Hsein-Wen Chao1*, Y. R. Chen2, S. C. Fong1, S. C. Chang2, T. S. Chin3, Tsun-Hsu Chang1
1Physics, National Tsing Hua University, Hsinchu, Taiwan
2Material Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan
3Materials Science and Engineering, Feng Chia University, Taichung, Taiwan
* presenting author:趙賢文, email:s9822817@m98.nthu.edu.tw
Using microwave to process material features shorter processing time and lower processing temperature, but to date the underlying mechanism is still under debate. A single-mode applicator is used to provide the precise control over the electromagnetic field. Nine alkali halogens of ionic crystals are selected. The reduction of the melting points were systematically characterized, where the lowest reduction is less than 2% for Lithium Bromide (LiBr) and the highest reduction is greater 5% for Potassium Fluoride (KF). The effective separation of the ionic bond strongly correlated to the melting point reduction. A theoretical model is proposed which considers the energy drop due to the dipolar property of the ionic crystal interacting with the applied microwave field.


Keywords: microwave, material processing, melting point, ionic crystal