Thermal diffusivity measurements of the layered materials by the laser flash method

Megumi Akoshima, Tetsuya Baba, Mitsue Ogawa, Takashi Tanaka, Yoshio Harada, Akira Kawasaki, Fumio Ono

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Citations (Scopus)

Abstract

Ceramics-based thermal barrier coatings are used as heat and wear shields of blades of gas turbine. There are strong needs to evaluate thermophysical properties of coatings, such as thermal conductivity, thermal diffusivity and heat capacity of them. Since coatings are attached on substrates, it is not easy to measure these properties separately. In order to evaluate the thermal diffusivity of coating attached on substrate, we have tried to apply the multi-layer model based on the response function method and established a procedure for the measurement by the laser flash method. We verified the procedure by the measurements from room temperature to about 1000 K for two-layer ceramics sample prepared by the doctor blade tape casting method. The thermally sprayed CoNiCrAlY coating on the SUS304 substrate was also used for verification. The thermal diffusivity of coating attached on substrate approximately agreed with that of the single-layer coating removed from substrate. In the case of the ceramics sample, the thermal diffusivity of the coating including the interfacial thermal resistance determined within about 20 % uncertainty. We compared the laser flash measurement signals of the samples prepared by the thermal spraying with variant thickness and found the difference among them. It was found that the procedure has enough resolution to detect the heat shield effect caused by the change with about 200 μm in thickness. The result shows that the procedure and analysis were practically effective for the thermal diffusivity estimation of coating attached on the substrate without remove from substrate.

Original languageEnglish
Title of host publicationMultiscale, Multifunctional and Functionally Graded Materials
PublisherTrans Tech Publications Ltd
Pages103-108
Number of pages6
ISBN (Print)0878493077, 9780878493074
DOIs
Publication statusPublished - 2010
Event10th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials, MM and FGMs - Sendai, Japan
Duration: 2008 Sep 222008 Sep 25

Publication series

NameMaterials Science Forum
Volume631-632
ISSN (Print)0255-5476
ISSN (Electronic)1662-9752

Other

Other10th International Symposium on Multiscale, Multifunctional and Functionally Graded Materials, MM and FGMs
CountryJapan
CitySendai
Period08/9/2208/9/25

Keywords

  • Laser flash method
  • Layered material
  • Thermal barrier coating
  • Thermal diffusivity

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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