Simultaneous measurement of dimensional and mass changes in bulk ceramics during sintering with a novel in-situ measurement technique

Abstract

A visual high-temperature deformation-thermogravimetric synchronous measurement system (TA-17AG) was built in this study to solve the problem that deformation and mass loss cannot be measured synchronously. First, the structure and working principle of the equipment were introduced, and the measurement accuracy of the equipment was verified by sintering experiments. Experimental results showed that the device could accurately measure the dimensional and mass changes in the bulk sample during sintering. Second, the sintering behavior of Al2O3 samples was analyzed based on the experimental data. The results showed that the mass change in the bulk sample was larger than that in the powder sample, and the maximum mass change rate of the bulk sample occurred in the low-temperature region. A strong correlation was observed between the dimensional and mass changes of the Al2O3 bulk sample, that is, the strain rate changed synchronously with the mass change rate. On the basis of the density data, the densification mechanism of Al2O3 was analyzed. When the relative density is 80 %, the apparent activation energy of Al2O3 densification is 389 kJ/mol. Last, because of the test results, the sintering process of the Al2O3 bulk sample was optimized. After optimization, the relative density and flexural strength of the sample increased to 97.7 ± 0.2 % and 386 ± 26 MPa, respectively, which were 0.7 % and 14.2 % higher than the values before optimization, respectively. The findings show that the TA-17AG system can provide reliable technical support for optimizing the sintering process of ceramic materials.

Keywords

• Simultaneous measurement technology
• High-temperature deformation
• Thermal weight loss
• Sintering kinetics
• Sintering process optimization