Thermal shock cracking of GSO single crystal
Miyazaki Noriyuki; Tamura Takaharu; Yamamoto Kazunari; Kurashige Kazuhisa; Ishibashi Hiroyuki; Susa Kenzo
Abstract:The quantitative estimation of the failure stress of a gadolinium orthosilicate (Gd2SiO5, hereafter abbreviated as GSO) single crystal due to thermal shock was investigated. A cylindrical test specimen was heated in a silicone oil bath, then subjected to thermal shock by pouring room temperature silicone oil. Cracking occurred during cooling. The heat conduction analysis was performed to obtain temperature distribution in a GSO single crystal at cracking, using the surface temperatures measured in the thermal shock cracking test. Then the thermal stress was calculated using temperature profile of the test specimen obtained from the heat conduction analysis. It is found from the results of the thermal stress analysis and the observation of the cracking in test specimens that the thermal shock cracking occurs in a cleavage plane due to the stress normal to the plane. Three point bending tests were also performed to examine the relationship between the critical stress for thermal shock cracking and the three point bending strength obtained from small sized test specimens. Key Words:finite element method, material testing, thermal stress, thermal shock, cracking, failure stress, GSO single crystal