AP40 glass-ceramic coatings on TiAl6V4 substrate were deposited by an atmospheric plasma spraying (APS) process. The morphology, microstructure and phase compositions of the coatings were studied by means of optical, scanning electron microscope and X-ray analysis. The effects of heat treatment on the microstructure and mechanical properties of coatings were also investigated.
The tensile bonding strength of the coating was evaluated in accordance with the DIN 50160. The results show that the coatings have low crystallinities. The spray parameters influence significantly both the porosity of the coatings and the deposition efficiency. A suitable heat-treatment can increase the coating crystallinity, reduce the porosities and increase the bond strength.