Applied Surface Science, Vol.257, No.24, 10828-10833, 2011
Improvement in the properties of plasma-sprayed metallic, alloy and ceramic coatings using dry-ice blasting
Dry-ice blasting, as an environmental-friendly method, was introduced into atmospheric plasma spraying for improving properties of metallic, alloy and ceramic coatings. The deposited coatings were then compared with coatings plasma-sprayed using conventional air cooling in terms of microstructure, temperature, oxidation, porosity, residual stress and adhesion. It was found that a denser steel or CoNiCrAlY alloy coating with a lower content of oxide can be achieved with the application of dry-ice blasting during the plasma spraying. In addition, the adhesive strength of Al(2)O(3) coating deposited with dry-ice blasting exceeded 60 MPa, which was nearly increased by 30% compared with that of the coating deposited with conventional air cooling. The improvement in properties of plasma-sprayed metallic, alloy and ceramic coatings caused by dry-ice blasting was attributed to the decrease of annulus-ringed disk like splats, the better cooling efficiency of dry-ice pellets and even the mechanical effect of dry-ice impact. (C) 2011 Elsevier B.V. All rights reserved.
Keywords:Atmospheric plasma spraying;Dry-ice blasting;Steel coating;CoNiCrAlY coating;Al(2)O(3) coating