Phase compositions and microstructure of plasma sprayed wollastonite coating

The phase compositions and microstructure of wollastonite coatings deposited onto Ti–6Al–4V substrates by plasma spraying were studied using scanning electron microscopy, X-ray diffraction and transmission electron microscopy. The plasma sprayed wollastonite coating was not homogeneous and had a rough surface. Some pores and microcracks existed in the coatings. The primary crystalline phase in the coating was triclinic wollastonite. Some crystalline wollastonite grains had dislocation. The glassy phase was also discovered with some small size crystals in the coating. In addition, tridymite (SiO2) and CaO were also found in the coating.