Determining thermal conductivity of plasma sprayed TBC by electrochemical impedance spectroscopy

2005 ◽  
Vol 190 (1) ◽  
pp. 90-97 ◽  
Author(s):  
J. Zhang ◽  
V. Desai
Keyword(s):  
Thermal Conductivity ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Plasma Sprayed

scholarly journals The Effect of Graphite Addition on Thermal Conductivity, Microstructure, and Electrochemical Impedance Spectroscopy of AlN Ceramics

2021 ◽  
Author(s):  
Tun Wang ◽  
Jianjun Xie ◽  
Lei Zhang ◽  
Tao Lu ◽  
Maomao Ding ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Activation Energy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Reduction Reaction ◽  
Oxygen Impurity ◽  
Carbon Reduction ◽  
Defects And Impurities ◽  
Multiphase Ceramics

Abstract Graphite/ aluminum nitride (AlN) multiphase ceramics are pressureless sintered under 1850°C using Dy2O3 and CaF2 as sintering additives. The effects of added graphite on microstructure, thermal conductivity, and electrochemical impedance spectroscopy of AlN ceramics were investigated. It was found that with 1wt% graphite addition the thermal conductivity of AlN in the through-plane to can achieve 210W/(m·K), which 25% higher than that of AlN without graphite. The graphite addition eliminates the oxygen impurity in AlN by a carbon reduction reaction in form of nanosized Dy2O3 particles. From electrochemical impedance spectroscopy manifested that the activation energy (Ea,g) of samples in grains is increased from 0.784 eV to 1.112 eV, suggesting that the concentrations of defects and impurities of Graphite/AlN multiphase ceramics are lower than those of monophase AlN ceramics.

Sign in / Sign up

Export Citation Format

Share Document