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Determination of interdiffusion coefficients of Si and Al in Ti 3 SiC 2 –Ti 3 AlC 2 diffusion couple at 1373‐1673 K
Author(s) -
Zhang Zerong,
Yin Xiaohui,
Qian Yuhai,
Xu Jingjun,
Zuo Jun,
Li Meishuan
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.16723
Subject(s) - electron microprobe , diffusion , analytical chemistry (journal) , electron probe microanalysis , chemistry , silicon , phase (matter) , materials science , mineralogy , thermodynamics , metallurgy , physics , organic chemistry , chromatography
In the diffusion couple of Ti 3 SiC 2 and Ti 3 AlC 2 , only interdiffusion of Si and Al occurred during diffusion treatment process. Based on the concentration profiles of Si and Al measured by electron probe microanalysis (EPMA), the interdiffusion coefficients of Si and Al at 1373‐1673 K in Ti 3 SiC 2 –Ti 3 AlC 2 diffusion couple were determined by both the Boltzmann‐Matano (B‐M) method and the Saucer‐Freise (S‐F) method. At the position of Matano plane with the composition of Ti 3 Al 0.5 Si 0.5 C 2 , the interdiffusion coefficient could be expressed as D int (m 2 /s) = 5.6 × 10 −4 ⋅exp [−246 ± 14 (kJ/mol)/RT]. Based on the two methods, the calculated interdiffusion coefficients increased with increasing temperature, and the magnitudes of their absolute values were on the order of 10 –13 ‐10 –11 m 2 /s at 1373‐1673 K. At 1373‐1573 K, the calculated interdiffusion coefficients decreased monotonously with the increase of Si concentration, that is, x Si /( x Al + x Si ). But at 1673 K, the variation trend of interdiffusion coefficients with x Si /( x Al + x Si ) was no longer monotonous, probably due to the presence of Ti 5 Si 3 phase and voids on Ti 3 AlC 2 side.