Mass spectrometric study and modeling of the thermodynamic properties in the Gd O -ZrO -HfO system at high temperatures.

Rationale: Materials based on the Gd O -ZrO -HfO system are promising for a wide range of high-temperature technological applications, such as for obtaining thermal barrier coatings in the aviation and space industry, as well as advanced materials in nuclear power applications. Experimental studies of the ceramics based on this system by the Knudsen effusion mass spectrometric method provides such valuable information as the vapor composition over the samples and enables derivation of the thermodynamic functions.

Methods: Samples of ceramics in the Gd O -ZrO -HfO system were synthesized and analyzed by X-ray fluorescence and diffraction techniques.

High-temperature mass spectrometric study of the thermodynamic properties in the Sm O -ZrO -HfO system.

Rationale: The Sm O -ZrO -HfO system is a promising base for the development of a wide spectrum of new refractory materials. Reliable data on thermodynamic properties in this system are of significant importance for planning the preparation and application of high-temperature ceramics. Especially, they can be useful for calculation of the unknown phase equilibria in this system.

Mass spectrometric study of ceramics in the Sm O -ZrO -HfO system at high temperatures.

Rationale: Systems containing zirconia, hafnia, and rare earth oxides are indispensable in various areas of high-temperature technologies as a basis of ultra-high refractory ceramics. Exposure of these materials to high temperatures may result in unexpected selective vaporization of components or phase transitions in the condensed phase leading to changes in physicochemical properties. Consequently, reliable application of the ceramics based on systems such as Sm O -ZrO -HfO is impossible without data on its vaporization processes and thermodynamic properties, which may be used to predict the physicochemical characteristics of the ultra-high refractory ceramics.

Vaporization and thermodynamics of ceramics in the Sm O -Y O -HfO system.

Rationale: The Sm O -Y O -HfO system holds promise for applications in the sphere of high-temperature technologies, particularly the development of ultra-high-temperature ceramics. However, the reliability of refractory materials is dependent on the possible selective vaporization of their components leading to changes in their physicochemical properties. Thus, information about vaporization processes and thermodynamic properties of ceramics based on the Sm O -Y O -HfO system may be of importance for the production of high-temperature materials as well as for the prediction of the physicochemical properties of ultra-high-temperature ceramics.

Vaporization and thermodynamics of ceramics in the Y O -ZrO -HfO system.

Rationale: The Y O -ZrO -HfO system is a promising base for a wide range of high-temperature materials including ultra-high-temperature ceramics. At high temperatures of synthesis and application of these ceramics the components may vaporize selectively, leading to changes in chemical composition and exploitation properties of the materials. Therefore, study of the vaporization processes of ceramics based on the Y O -ZrO -HfO system is of great importance.

Vaporization and thermodynamics of ceramics based on the La O -Y O -HfO system studied by the high-temperature mass spectrometric method.

Rationale: Materials based on the La O -Y O -HfO system are promising for the production of highly refractory ceramics, e.g., thermal barrier coatings and molds for casting of elements of gas turbine engines.

High-temperature mass spectrometric study of the vaporization processes and thermodynamic properties in the Gd O -Y O -HfO system.

Rationale: The refractory properties of the Gd O -Y O -HfO system are considered promising for the production of many high-temperature materials, e.g., thermal barrier coatings and casting molds for gas turbine engine blades.

Mass spectrometric study of thermodynamic properties in the Gd O -Y O system at high temperatures.

Rationale: The Gd O -Y O system possesses a number of practical applications, one of the most important of them being production of casting molds for gas turbine engine blades. The components of this system are often added to zirconia or hafnia to obtain high-temperature ceramics which are used for the development of thermal barrier coatings. However, Gd O and Y O are more volatile than zirconia or hafnia and may vaporize selectively during synthesis or usage of high-temperature materials which may lead to changes in their physicochemical properties.