Synthesis of Ti3SiC2 coatings onto SiC monoliths from molten salts

Coatings with composition close to Ti3SiC2 were obtained on SiC substrates from Ti and Si powders with the molten NaCl method. In this work, the growth of coatings by reaction in the salt between monolithic SiC substrates and titanium powder is obtained between 1000 and 1200 ?. At 1000 ?, a coating of 8 mu m thickness is formed in 10 h whereas a thin coating of 0.5 mu m has been grown in 2 h. A lack in silicon was first found in the coatings prepared at 1100 and 1200 ?. For these temperatures, the addition of silicon powder in the melt had a favorable effect on the final composition, which is found very close to the composition of Ti3SiC2. The reaction mechanism implies the formation of TiCx layers in direct contact with the SiC substrate and the presence of more or less important quantities of Ti3SiC2 and Ti(5)Si(3)Cx in the upper layers.

Automated summary

Coatings close to Ti3SiC2 composition were successfully obtained on SiC substrates using the molten NaCl method. The growth of coatings between 1000 and 1200 ? was influenced by temperature, with the addition of silicon playing a key role in the final composition.