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Thermodynamics and kinetics of sintering of Y 2 O 3
Author(s) -
Nakajima Kimiko,
Castro Ricardo H. R.
Publication year - 2020
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17273
Subject(s) - sintering , activation energy , materials science , grain boundary diffusion coefficient , differential scanning calorimetry , microstructure , dihedral angle , grain boundary , yttrium , diffusion , thermodynamics , grain growth , surface diffusion , kinetics , kinetic energy , oxide , mineralogy , chemistry , metallurgy , adsorption , molecule , physics , hydrogen bond , organic chemistry , quantum mechanics
Surface energy ( γ S ) and grain boundary energy ( γ GB ) of yttrium oxide (Y 2 O 3 ) were determined by analyzing the heat of sintering (Δ H sintering ) using differential scanning calorimetry (DSC). The data allowed quantification of sintering driving forces, which when combined with a thorough kinetic analysis of the process, provide better understanding of Y 2 O 3 densification as well as insights into effective strategies to improve its sinterability. The quantitative thermodynamic study revealed moderate thermodynamic driving force for densification in Y 2 O 3 (as compared to other oxides) represented by a dihedral angle of 152.7° calculated from its surface and grain boundary energies. The activation energy was determined as 307 ± 61 kJ/mol, consistent with activation energies previously reported for processes relevant to sintering of Y 2 O 3, such as Y 3+ diffusion and grain boundary mobility. Finally, we propose that a refined deconvolution study on the DSC curve for Y 2 O 3 sintering, combined with the associated material's microstructure evolution, may help identify shifts in sintering mechanisms, and therefore, specific activation energies at increasing temperatures.