Development of an Apparatus for the Repeated Thermal Shock Test

• Published in: Transactions of the Japan Society of Mechanical Engineers Series C Vol. 57; no. 544; pp. 4029 - 4033
• Main Authors: KATSUMURA, Munehide, MATSUDA, Jun, MIYOSHI, Yoh, UTSUMI, Akihiro, KAGAWA, Seijiro, YONEDA, Masafumi
• Format: Journal Article
• Language: English; Japanese
• Published: The Japan Society of Mechanical Engineers 1991
• Subjects: Coating; Laser; Laser Spraying; Repeated Thermal Shock; Spraying; Thermal Barrier Coatings; Thermal Shock; Titanium Nitride
• ISSN: 0387-5024; 1884-8354
• DOI: 10.1299/kikaic.57.4029

Metallic materials with thermal barrier coatings are available under high temperatures (about 2000K). However, it is unknown whether or not the coating materials can resist repeated thermal shock. The authors have been developing laser spraying methods which can easily form metallic or ceramic coatings. In order to examine the characterestics of the coatings produced by the laser spraying methods, a new testing apparatus for repeated thermal shock was needed. Therefore, the testing apparatus was made on an experimental basis. The heat source of the apparatus was a carbon dioxide laser beam (maximum power supply: 5kW) and the tested materials were titanium nitride layers which were coated on mild steel plates by means of laser spraying methods. As a result of testing, the surface temperature reached 2000K in 4 seconds in the case of 290 W/cm2 (power supply: 4kW; beam diameter: 42mm), and it was possible to repeat thermal shocks between room temperature and 2000K (at the surface) or 1000K (at the bottom of the coating; thickness: 1mm) at the rate of 3 times a minute.