Thermal properties of single-phase Y2SiO5
Y(2)SiO(5) is a promising candidate for oxidation-resistant or environmental/thermal barrier coatings (ETBC) due to its excellent high-temperature stability, low elastic modulus and low oxygen permeability. In this paper, we investigated the thermal properties Of Y2SiO5 comprehensively, including thermal expansion, thermal diffusivity, heat capacity and thermal conductivity. It is interesting that Y(2)SiO(5) has a very low thermal conductivity (similar to 1.40 W/m K) but a relatively high linear thermal expansion coefficient ((8.36 +/- 0.5) x 10(-6) K(-1)), suggesting compatible thermal and mechanical properties to some non-oxide ceramics and nickel superalloys as ETBC layer. Y(2)SiO(5) is also an ideal EBC on YSZ TBC layer due to their close thermal expansion coefficients. As a continuous source of Y(3+), it is predicted that Y(2)SiO(5) EBC may prolong the lifetime of zirconia-based TBC by stopping the degradation aroused by the loss of Y stabilizer. (C) 2008 Elsevier Ltd. All rights reserved.