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Oxidation Kinetics of Zirconium Carbide at Relatively Low Temperatures
Author(s) -
Shimada Shiro,
Ishil Tadao
Publication year - 1990
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.1151-2916.1990.tb06678.x
Subject(s) - zirconium , kinetics , materials science , isothermal process , diffusion , oxygen , carbon fibers , activation energy , zirconium carbide , cubic zirconia , carbide , argon , analytical chemistry (journal) , chemical engineering , mineralogy , chemistry , thermodynamics , metallurgy , ceramic , composite material , physics , organic chemistry , chromatography , quantum mechanics , composite number , engineering
The isothermal oxidation of ZrC powders was carried out at relatively low temperatures of 380° to 550°C at oxygen pressures of 1.3, 2.6, and 7.9 kPa under a static total pressure of 39.5 kPa, achieved by mixing with argon, using an electromicrobalance. The oxidation kinetics are described by the diffusion‐controlled Jander's equation, following rapid oxidation in the early stage. Two activation energies were obtained: 138 kJ · mol −1 below about 470°C and 180 kJ · mol −1 above that temperature. The high‐ and low‐temperature oxidation mechanisms are discussed in connection with the crystallization of cubic ZrO 2 , accompanied by the generation of cracks, as well as the formation of carbon in the hexagonal diamond form in the product phase.