首页 | 本学科首页   官方微博 | 高级检索  
     


Reliability of laser flash thermal diffusivity measurements of the thermal barrier coatings
Authors:H Wang  R B Dinwiddie
Affiliation:(1) High Temperature Materials Laboratory, Oak Ridge National Laboratory, 37831-6064 Oak Ridge, TN
Abstract:The thermal diffusivity of free standing thermal barrier coatings (TBCs) was measured by the laser flash technique. The combination of low thermal conductivity (1 to 2 W/m K) and small TBC thickness (300 to 600 μm thick) can cause errors in the measurements. Back surface (opposite the laser) temperatures of free standing plasma-sprayed TBCs were measured as a function of time and laser power. The front surface temperatures were calculated using thermal transport equations. In the high power region, thermal diffusivity decreased significantly with increasing laser power. In the moderate power region, thermal diffusivity remained constant. In the low power region, measurement became unreliable because of noise. The detector nonlinearity was believed to be a possible cause of deviation in the high power region. Measurements at different laser power levels should be conducted in order to obtain reliable thermal diffusivity values for TBCs.
Keywords:TBC  thermal diffusivity  thermal conductivity  laser flash
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号