Mechanisms and Kinetics of the Hydrothermal Oxidation of Bulk Titanium Silicon Carbide
Abstract:Hydrothermal oxidation of bulk Ti3SiC2 in continuous water flow was studied at 500°–700°C under a hydrostatic pressure of 35 MPa. The oxidation was weak at 500°–600°C and accelerated at 700°C due to the formation of cracks in oxides. The kinetics obeyed a linear time-law. Due to the high solubility of silica in hydrothermal water, the resulting oxide layers only consisted of titanium oxides and carbon. Besides general oxidation, two special modes are very likely present in current experiments: (1) preferential hydrothermal oxidation of lattice planes perpendicular to the c-axis inducing cleavage of grains and (2) uneven hydrothermal oxidation related to the occurrence of TiC and SiC impurity inclusions. Nonetheless the resistance against hydrothermal oxidation is remarkably high up to 700°C.
Document Type: Research Article
Affiliations: 1: Applied Mineralogy, Institute for Geosciences, Eberhard-Karls-Universität Tübingen, Wilhelmstraße 56, D-72074 Tübingen, Germany 2: Institute for Physics and Theoretical Chemistry, Eberhard-Karls-Universität Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany 3: Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
Publication date: April 1, 2010