Obtaining composites powders of Al2O3 / Ni and Al2O3 / Nb by mechanical alloying

Abstract

Mechanical alloying (MA) can be highlighted among the various methods and powder processing forms, which consists of producing homogeneous materials from elementary powders. This process is of paramount importance as it has the ability to reduce the particle size of the powders and can often promote bonding between elements which have low interaction and wettability. This method is usually used in the route of powder metallurgy, and generally improves the sinterability and mechanical properties of the materials. In this context, the objective of this work was to analyze the evolution of mixtures of Al2O3-5wt%-Ni and Al2O3-5wt%-Nb powders submitted to the mechanical alloying process in a planetary ball mill for up to 40h. The morphological evolution was observed through Scanning Electron Microscopy (Field Emission Gun, SEM-FEG), energy dispersive spectrometry (EDAX) phases and particle sizes by Particulometry. It was observed that a significant micro structural change occurred in both compositions, indicating the formation of composite powders. This behavior was more intensely observed with the increase in the grinding time, obtaining composite powders with a more homogeneous and uniform structure with the time of 40 hours of MA.