Liquid phase flash sintering in magnesia silicate glass-containing alumina

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• 作者：Mattia Biesuz^a ; ^{mattia.biesuz@unitn.it" class="auth_mail" title="E-mail the corresponding author} ; Vincenzo M. Sglavo^a ; ^b ; ^{vincenzo.sglavo@unitn.it" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Flash sintering ; Liquid phase sintering ; Alumina ; Glass softening
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：37
• 期：2
• 页码：705-713
• 全文大小：2931 K

文摘

Magnesia silicate glass-containing alumina was flash sintered using an E-Field in the 500–1500 V/cm range. The addition of glass allows to reduce the current needed for densification and improves the shrinkage obtained during field-assisted sintering process. This behaviour is related to the different sintering mechanisms involved in the two materials, i.e. solid state sintering for pure alumina and liquid phase sintering for glass-containing alumina.

The estimated activation energy for conduction during flash sintering is compatible with ionic diffusion in silicate melt. Moreover, evidence of magnesium diffusion toward the cathode is recorded. The estimated sample temperature is in almost all cases lower than 1355 °C, which is the temperature at which the first liquid is formed in the ternary system MgO-SiO₂-Al₂O₃. Finally, it is shown that the application of an E-Field accounts for efficient liquid phase sintering at temperatures at which it cannot be reproduced conventionally.