Effect of environmental factors on thermal shock behaviour of polycrystalline alumina ceramics

• Published in: Journal of materials science Vol. 34; no. 15; pp. 3623 - 3630
• Main Authors: Hahn, Bong Seok, Lee, Hong Lim
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.08.1999; Springer Nature B.V
• Subjects: Aluminum oxide; Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Ceramics; Chemical industry and chemicals; Cooling; Cooling rate; Cracks; Exact sciences and technology; Heat transfer coefficients; Materials science; Miscellaneous; Polycrystals; Propylene; Quenching media; Technical ceramics; Thermal shock; Thermal stress; Thermal stress; Thermal shock resistance; Polycrystal; Quenching medium; Environmental effect; Thermomechanical properties; Experimental study; Alumina; Oxide ceramics; Heat transfer
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/A:1004686918618

The effect of the environmental factors on thermal shock behaviour of polycrystalline alumina ceramics was studied by quenching the alumina specimens into various quenching media. The environment factors of quenching media were controlled by changing the temperature of water and changing the concentration of the propylene glycol/water solution. The convection heat transfer coefficient and thermal stress increased as the temperature of cooling water increased and decreased as the concentration of the propylene glycol in water increased. The critical thermal stress which makes the cracks grow catastrophically was found to be generated by the critical cooling rate, and the critical cooling rate of alumina ceramics was found to be a certain value (550 °C/s) and same for all cooling liquids. Therefore, cooling rate was found to be the most influential of the environmental factors in thermal shock.