Thermal Diffusivity of TBC Layers of RE2Zr2O7 Type

2011 ◽  
Vol 312-315 ◽  
pp. 445-450 ◽  
Author(s):  
Grzegorz Moskal
Keyword(s):  
Thermal Diffusivity ◽  
Double Layer ◽  
Single Layer ◽  
Laser Flash ◽  
Ceramic Layer ◽  
Flash Method ◽  
Air Plasma ◽  
Double Layer Model ◽  
Layer Sample ◽  
New Type

The paper presents the results of basic thermal properties of thermal barrier coatings on the base of rare earth zirconate of type Gd2Zr2O7, deposited by the air plasma spraying (APS) method. Measurements of thermal diffusivity with the laser-flash method were performed within the temperature range of 25°C-1100°C with two and ten hours of annealing. The measurements were performed on the single-layer (AMS 5599 alloy), double-layer (AMS 5599 alloy + NiCrAlY interlayer) and three-layer samples (AMS 5599 alloy + NiCrAlY interlayer + ceramic layer of RE2Zr2O7). By using the NETZSCH Proteus software and the results for the single-layer sample, thermal diffusivity of the interlayer itself was determined by means of the double-layer model. A similar method was used to determine the thermal diffusivity of the ceramic layer. The obtained results showed lower thermal diffusivity and thermal conductivity for the new type of coatings in comparison with the standard zirconium concerning TBCs. Those results are slightly different compared with the results obtained for the initial powders, which indicates a crucial role of the ceramic layer microstructure (architecture of cracks and porosity).

Thermal Diffusivity Measurements of the Layered Materials by the Laser Flash Method

2009 ◽  
Vol 631-632 ◽  
pp. 103-108 ◽  
Author(s):  
Megumi Akoshima ◽  
Tetsuya Baba ◽  
Mitsue Ogawa ◽  
Takashi Tanaka ◽  
Yoshio Harada ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Tape Casting ◽  
Thermal Spraying ◽  
Single Layer ◽  
Laser Flash ◽  
Laser Flash Method ◽  
Interfacial Thermal Resistance ◽  
Flash Method ◽  
Properties Of Coatings ◽  
The Difference

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 m 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.

Study of the Thermal Diffusivity Variation in Thin Duplex Steel Plates Welded by GTAW Process

2018 ◽  
Vol 930 ◽  
pp. 460-465
Author(s):  
Evandro Giuseppe Betini ◽  
Maurilio Pereira Gomes ◽  
Cristiano Stefano Mucsi ◽  
Temístocles de Souza Luz ◽  
Marcos Tadeu D'azeredo Orlando ◽  
...  
Keyword(s):  
Thermal Diffusivity ◽  
Welding Process ◽  
Laser Flash ◽  
Nitrogen Atmosphere ◽  
Steel Plates ◽  
Digital Data ◽  
Flash Method ◽  
Temperature Profiles ◽  
Butt Weld ◽  
Duplex Steel

This study describes the thermal diffusivity of thin duplex steel plates in the thickness direction measured using the laser-flash method after welding. The work reports the experimental efforts in recording temperature profiles of the grade UNS S32304 duplex steel during autogenous welding. The butt weld autogenous joints were carried out by the GTAW (gas tungsten arc welding) process with either argon or argon - 2% nitrogen atmospheres. The amount of nitrogen in the heat affected regions, after welding, was measured and correlated with the variation of the thermal diffusivity of the studied material. The temperature profiles were obtained using k-type thermocouples connected to a digital data acquisition system. Different thermal cycles and thermal diffusivity values were observed in the heat-affected zone (HAZ) for both samples. In the solidified zone (SZ) was observed similar increase of the thermal diffusivity values for the plates welded with pure argon and argon plus nitrogen atmosphere.

A high-temperature system based on the laser flash method to measure the thermal diffusivity of melts

1996 ◽  
Vol 17 (1) ◽  
pp. 253-261 ◽  
Author(s):  
Y. Maeda ◽  
H. Sagara ◽  
R. P. Tye ◽  
M. Masuda ◽  
H. Ohta ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Diffusivity ◽  
Laser Flash ◽  
Laser Flash Method ◽  
Flash Method ◽  
High Temperature System

scholarly journals Measurement of Thermal Diffusivity of Steels at Elevated Temperature by a Laser Flash Method.

2002 ◽  
Vol 42 (5) ◽  
pp. 498-503 ◽  
Author(s):  
Tsuyoshi Nishi ◽  
Hiroyuki Shibata ◽  
Koichi Tsutsumi ◽  
Hiromichi Ohta ◽  
Yoshio Waseda
Keyword(s):  
Elevated Temperature ◽  
Thermal Diffusivity ◽  
Laser Flash ◽  
Laser Flash Method ◽  
Flash Method

scholarly journals Thermal diffusivity of corrosion-resistant coating SDP-1

2021 ◽  
Vol 2119 (1) ◽  
pp. 012145
Author(s):  
A Sh Agazhanov ◽  
D A Samoshkin ◽  
S V Stankus
Keyword(s):  
Thermal Diffusivity ◽  
Wide Temperature Range ◽  
Laser Flash ◽  
Flash Method ◽  
Corrosion Resistant ◽  
Practical Applications ◽  
Temperature Range ◽  
Resistant Coating ◽  
Heat Resistant Coating ◽  
Corrosion Resistant Coating

Abstract In the present work, the thermal diffusivity of the SDP-1 grade nickel alloy was investigated in the wide temperature range of 300-1476 K. The SDP-1 alloy (Ni-Co-Cr-Al-Y) is the heat-resistant coating for blades of gas turbine plants, providing protection against sulfide-oxide corrosion in the temperature range of 1070-1220 K. The measurements were performed by laser flash method using LFA-427 apparatus. The estimated errors of the obtained data were 2-5% depending on temperature. The thermal diffusivity approximation equations and a table of reference values for various scientific and practical applications were obtained.

Thermal Diffusivity of 16Kh12V2FTaR Steel in a Wide Temperature Range

2013 ◽  
Vol 8 (3) ◽  
pp. 163-167
Author(s):  
Alibek Agazhanov ◽  
Igor Savchenko ◽  
Dmitriy Samoshkin ◽  
Sergey Stankus ◽  
Olga Dutova
Keyword(s):  
Phase Transitions ◽  
Thermal Diffusivity ◽  
Wide Temperature Range ◽  
Curie Point ◽  
Martensitic Steel ◽  
Laser Flash ◽  
Austenite Phase ◽  
Laser Flash Method ◽  
Flash Method ◽  
Temperature Range

Thermal diffusivity of the ferritic-martensitic steel 16Kh12V2FTaR in the temperature range from 296 to 1274 K has been measured by the laser flash method with the error of 2–4 %. The approximating equations have been obtained, the Curie point of steel and the temperatures of martensitic-austenite phase transitions have been determined

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