The chemical composition, the particle size distribution and the crystallographic phases of the feedstock powders used to manufacture the coatings are shown in Table 1. The chemical composition results indicate that mainly Al2O3constitute these materials, with particle size distributions between ≈21 μm and ≈64 μm. The main phase in the both feedstock powders was α-Al2O3and additionally, in the fused & crushed one a low quantity of γ-Al2O3was also detected.
Table 1 Main physical-chemical features of the feedstock powders
The morphological analysis indicated that the agglomerated powder shows rounded particles constituted by small bonded sub-micrometrical particles (Fig. 1a), evidencing that this powder was manufactured by agglomeration processes, while all particles of the fused & crushed powder were irregular with fracture marks in their surface (Fig. 1b),evidencing that this powder was manufactured by fusing and crushing processes.
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