Tantalum carbide is a ceramic material that is extremely hard and has a high melting point. It is used as a sintering additive in a wide range of applications and it is one of the most popular materials for manufacturing composite materials. Moreover, tantalum carbide coatings can be applied to graphite in order to produce highly reliable protective coatings.
The objective of this work is to develop a method for producing low-cost protective coatings on graphite substrates using a new tantalum carbide (TaC) ceramic, which can be prepared by applying a TaC slurry and subsequent sintering in a conventional ceramic process. The resulting sintering is characterized by high adhesion, which is particularly important for the production of coatings for crucibles and susceptors used in physical vapor transmission (PVT) crystal growth processes that use wide bandgap materials.
In addition to high adhesion, the sintering is also characterized by a very dense and coarse granular structure and by no pinholes. The morphological characteristics of the coatings have been examined by X-ray analysis and metallography. The microstructures of Fe/TaC coatings remelted by laser processing were analyzed in three different areas of the remelted zone for various laser beam powers, and they all showed a matrix composed of primary Tig dendrites surrounded by interdendritic eutectic lattices of complex carbides formed at grain boundaries. The results demonstrate that the proposed sintering can be used for the production of very thin (
