A new application field of plasma spraying technique to environmental depollution

摘要

To expand the application of plasma spraying technique, TiO_2 coatings were prepared using agglomerated anatase TiO_2 powder to solve the environmental problems. The composition and photocatalytic activity of plasma sprayed TiO_2 coatings were investigated systematically. The content of anatase TiO_2 in the sprayed coatings was approximate to 7%- 15% , which was influenced by the melting state of TiO_2 powder in plasma spraying process. The surface of sprayed coating was very rough and the arithmetical mean deviation of the surface profiles (R_a) was in the range of 5. 7 - 8. 8 μm. Under lower arc current, the surface of the coating became rougher. The anatase to rutile phase transformation temperature of agglomerated anatase TiO_2 powder was approximate to 1 173 K. The TiO_2 coating sprayed under the arc current of 400 A had good photocatalytic activity for the relative high content of anatase phase in it. It is concluded that the application of plasma spraying technique to environmental field has been developed.