The effect of deposition temperature on the microstructure and mechanical properties of TaC coatings

• Tantalum carbide (TaC) coatings were produced by CVD at different temperatures.
• Microstructure and mechanical properties were studied as a function of deposition temperature.
• Mechanical properties were affected significantly due to the variation in microstructure.

Tantalum carbide (TaC) coatings were produced on carbon/carbon composites by chemical vapor deposition. The effect of deposition temperature on the structure and mechanical properties were investigated. X-ray diffraction results showed that the coatings exhibited a single phase cubic structure. For the coating produced at 1300 °C, the carbon as a minor impurity phase was detected using Raman spectroscopy. Scanning electron microscopy analysis showed smooth and crack free coatings produced at 1100 °C and 1200 °C. At higher temperature, the hardness and Young׳s modulus were found to be affected due to the (i) presence of carbon as a minor impurity phase and (ii) variation in grain size.