Recycling of Waste Powder Material of a Thermal Spray Shop

摘要

A very fine powder, which is the waste material of Pyrogenesis S.A thermal spray shop, consisted of a metallic (Al, Mo, Fe-based), a ceramic (alumina, chromia, zirconia) and a carbide (tungsten carbide and chromium carbide) part, was investigated for its possibilities to be recycled and used as a thermal spraying feedstock material. For this purpose, the fine powder was dispersed in water and the slurry prepared was spray dried in a Buchi laboratory spray dryer. Spherical particles were received by this way in the proper size range (10-50 μm) for the thermal spraying process. The material was thermally sprayed by careful adjustment of the spraying parameters and the coatings were characterized in terms of their crystallinity, morphology, microstructure, mechanical properties and adhesion strength. The thermal spraying of the as-treated reclycled material led to coatings of acceptable quality with good morphology and adhesion strength. The coatings were multicomponent consisted mainly of aluminium, chromia, alumina and tungsten carbide phases. The hardness of the phases present in the coating varied between 71 to 792 FfV with the average hardness of the coating measured at 197 HV.