Plasma sprayed coatings of glass microspheres premixed with Al2O3particles

Plasma sprayed coatings are widely used these days to improve wear, thermal and corrosion resistance of machine components. Although much work have been reported on such coatings made up of a large number of metals and ceramic particles, no effort has so far been made with glass microspheres for this purpose despite its high hardness. In view of this, the present work is undertaken to study the preparation and characterisation of a new class of coatings made up of borosilicate glass microspheres (BGMs) premixed with microsized aluminium oxide (Al 2 O 3 ) in different proportions. Deposition of BGM/Al 2 O 3 coatings is done at five different torch input power. The coatings are characterised in terms of their thickness, hardness, adhesion strength, porosity and deposition efficiency. This work reveals that premixing of Al 2 O 3 results in improved properties in BGM coatings. With fairly good hardness and low porosity, these coatings can be used in many engineering applications.