Chemical Stability between NiCr2O4 Material and Molten Calcium-Magnesium-Alumino-Silicate (CMAS) at High Temperature
نویسندگان
چکیده
NiCr₂O₄ as a potential protection for thermal barrier coatings (TBCs) against the attack of molten calcium-magnesium-alumino-silicate (CMAS) was studied by a CMAS-contacting experiment. Atmospheric plasma sprayed coatings and sintered bulk materials were fabricated, covered with CMAS deposits, and exposed to 1200 °C for 24 h. Nano-sized CMAS-NiCr₂O₄ mixed powder was manufactured by ball milling and then conducted heat treatment under the same condition. The results show that no reacting product was found at the border between molten CMAS and NiCr₂O₄ and no element transportation occurred. It can be inferred that NiCr₂O₄ has outstanding chemical stability with the molten CMAS.
منابع مشابه
Mechanisms of cracking and delamination within thick thermal barrier systems in aero-engines subject to calcium-magnesium-alumino-silicate (CMAS) penetration
Mechanisms of cracking and delamination within thick thermal barrier systems in aero-engines subject to calcium-magnesium-alumino-silicate (CMAS) penetration S. Krämer a,∗, S. Faulhaber a, M. Chambers a, D.R. Clarke a, C.G. Levi a, J.W. Hutchinson b, A.G. Evans a a Materials Department, University of California, Santa Barbara, CA 93106-5050, United States b Division of Engineering and Applied S...
متن کاملCalcium-Magnesium-Aluminosilicate (CMAS) Reactions and Degradation Mechanisms of Advanced Environmental Barrier Coatings
The thermochemical reactions between calcium-magnesium-aluminosilicate(CMAS-) based road sand and several advanced turbine engine environmnetal barrier coating (EBC) materials were studied. The phase stability, reaction kinetics and degradation mechanisms of rare earth (RE)-silicates Yb2SiO5, Y2Si2O7, and RE-oxide doped HfO2 and ZrO2 under the CMAS infiltration condition at 1500 C were investi...
متن کاملNovel geopolymeric material cured at room temperature
Alkali activated binders are a new class of binding material with comparable or enhanced performance to Portland cement. These binding materials are obtained by a chemical reaction between an alumino-silicate material and a highly alkaline solution. In most cases, the setting-hardening process of this binder is performed at high curing temperatures. In this paper, alkali activated mortars based...
متن کاملDelamination Susceptibility of Coatings Under High Thermal Flux
Delamination of coatings initiated by small cracks paralleling the free surface is investigated under conditions of high thermal flux associated with a through-thickness temperature gradient. A crack disrupts the heat flow thereby inducing crack tip stress intensities that can become critical. A complete parametric dependence of the energy release rate and mode mix is presented in terms of the ...
متن کاملDevelopment of Sustainable Cementitious Materials
In this paper, two types of sustainable cementitious composites, geopolymer and magnesium phosphate cement, are introduced. The geopolymer is a type of amorphous alumino-silicate products and magnesium cement is MgO based cementitious material. Geopolymer can be synthesized by polycondensation reaction of geopolymeric precursor, and alkali polysilicates. The MgO cement can be obtained by proper...
متن کامل