ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract An experimental study of the deposition of Ti3SiC2-based ceramics from TiCI4-SiCI4-CH4-H2 gaseous precursors is carried out under conditions chosen on the basis of a previous thermodynamic approach, i.e. a temperature of 1100°C, a total pressure of 1 7 kPa, various initial compositions and substrates of silicon or carbon. Ti3SiC2 is deposited within a narrow composition range and never as a pure phase. A two-step deposition process is observed, in agreement with the thermodynamic calculations. For a silicon substrate, TiSi2 is formed as an intermediate phase from consumption of Si by TiCI4 and then is carburized by CH4 into Ti3SiC2. For a carbon substrate, the first step is the formation of TiCx either from consumption of carbon by TiCI4 or by reaction between TiCI4 and CH4 and then TiCx reacts with the gaseous mixture to give rise to Ti3SiC2. In most cases, Ti3SiC2 is obtained as small hexagonal plates oriented perpendicular to the substrate surface. These nano- or micro-crystals are usually co-deposited with TiCx and to a lesser extent SiC, and their size is increased by increasing the dilution of the gaseous mixture in hydrogen.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00355952
Permalink
