Acoustic emission study of quartz porcelain during heating up to 1150 degrees C

作者：Stubna Igor; Chmelik Frantisek; Trnik Anton^*; Sin Peter

来源：Ceramics International, 2012, 38(8): 6919-6922.

DOI：10.1016/j.ceramint.2012.05.021

• Acoustic emission
• Microcracks
• Young%26apos
• s modulus
• Quartz porcelain

The acoustic emission (AE) technique was used for the real-time monitoring of microcracking in a green quartz porcelain mixture (50 wt% kaolin, 25 wt% quartz and 25 wt% feldspar) subjected to heating up to 1150 degrees C with a heating rate of 5 degrees C/min. Two sources of microcracking were identified. The first one, which begins at a temperature of 50 degrees C, is connected to the liberation of physically bound water. The second source is caused by differences between the thermal expansion of crystals (kaolinite/metakaolinite, feldspar and alpha-quartz/beta-quartz). The alpha -%26gt; beta transformation of quartz is not detected with AE. The vanishing of cracking at 600 degrees C correlates with the increase of the Young%26apos;s modulus and is ascribed to solid-state sintering, which fortifies crystal interfaces between metakaolinite, feldspar and beta-quartz.

• 出版日期2012-12