Premium
Adjacent relations of primary phase fields and invariant reactions of the system CaO‐SiO 2 ‐Nb 2 O 5 ‐La 2 O 3
Author(s) -
Liu Chengjun,
Qiu Jiyu,
Liu Zhengyue,
Zhu Deying,
Wang Yeguang,
Jiang Maofa
Publication year - 2021
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.17605
Subject(s) - phase diagram , liquidus , tetrahedron , phase rule , thermodynamics , solid solution , diagram , materials science , phase (matter) , mineralogy , crystallography , chemistry , physics , mathematics , metallurgy , organic chemistry , statistics
The adjacent relation of primary phase fields and corresponding invariant reactions of the system CaO‐SiO 2 ‐Nb 2 O 5 ‐La 2 O 3 are of great importance for the study on its phase diagram. In the present work, the phase equilibrium in the high w (La 2 O 3 ) region of CaO‐SiO 2 ‐Nb 2 O 5 ‐La 2 O 3 system was studied by thermodynamic equilibrium experiment. The adjacent relation of primary phase fields was determined and represented in the form of adjacent tetrahedrons. The Alkemade Rule applicable to quaternary phase diagram was deduced, which can be used to infer the liquidus temperature trend on univariant curves. The rule was then used to determine the possible temperature range of invariant reactions corresponding to the adjacent tetrahedron in CaO‐SiO 2 ‐Nb 2 O 5 ‐La 2 O 3 system, and the result was shown in the form of Schairer diagram. Finally, the reaction types of five invariant points were determined according to the Lever Rule for quaternary phase diagram, including: ① L 1 +CaO·3SiO 2 ·2La 2 O 3 →CaO·SiO 2 +SiO 2 +La 2 O 3 ·Nb 2 O 5 , ② L 2 →CaO·SiO 2 +La 2 O 3 ·Nb 2 O 5 +SiO 2 +CaO·Nb 2 O 5 , ③ L 3 +CaO·3SiO 2 ·2La 2 O 3 +2CaO·Nb 2 O 5 →10CaO·6SiO 2 ·Nb 2 O 5 +La 2 O 3 ·Nb 2 O 5 , ④ L 4 +10CaO·6SiO 2 ·Nb 2 O 5 →CaO·SiO 2 +2CaO·Nb 2 O 5 +La 2 O 3 ·Nb 2 O 5 , ⑤ L 5 +2CaO·Nb 2 O 5 →CaO·Nb 2 O 5 +La 2 O 3 ·Nb 2 O 5 +CaO·SiO 2 .