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Oxidation/Vaporization Kinetics of Cr 2 O 3
Author(s) -
GRAHAM H. C.,
DAVIS H. H.
Publication year - 1971
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/j.1151-2916.1971.tb12225.x
Subject(s) - vaporization , partial pressure , oxidizing agent , chemistry , evaporation , kinetics , pellets , total pressure , thermodynamics , analytical chemistry (journal) , volumetric flow rate , materials science , oxygen , chromatography , composite material , organic chemistry , physics , quantum mechanics
The weight loss of Cr 2 O 3 in oxidizing environments (Po 2 = 1 to 10 −3 atm) at 1200°C was measured. Both hot‐pressed and sintered Cr 2 O 3 pellets were investigated in O 2 /Ar gas mixtures, and the dependence of the weight loss on the O 2 partial pressure, the gas flow rate, and the total pressure was determined independently. The experimentally determined O 2 partial pressure dependence (rate ∝ PO 2 3/4 ) corresponds to that expected for the reaction Cr 2 O 3 (s)+3/2O 2 ⇌2CrO 3 (g). The flow rate and total pressure dependencies show that mass transport through a gaseous boundary layer is the rate‐controlling step in the oxidation/vaporization of Cr 2 O 3 . Evaporation coefficients for the loss of CrO 3 (g) under the experimental conditions were <0.01.