Comparative study of synthesis of AA 7075-ZrO2 metal matrix composite by different mills

The objective of using three different (planetary, horizontal attritor, and shaker) ball mills in the synthesis of AA 7075-ZrO2 metal matrix composite is to assess their effectiveness in dispersing ZrO2 nanosized particles through the matrix in each individual milling process. The results show that in the case of the planetary ball mill, a full dispersion of the ZrO2 through the matrix can be achieved because an excess of the process control agent promotes the fracture of particles instead of welding, leading to the breakdown of ZrO2 agglomerates and achieving a complete dispersion of the reinforcement. In the case of the Simoloyer mill, the results showed that there was not a fine dispersion of the ZrO2 particles, because some ZrO2 clusters were of micrometer size, showing that the welding is the major process in this mill. On the other hand, the shaker mill (Spex) produced the best results, because full dispersion of the ZrO2 particles took place in a homogeneous way in half the time taken by the other mills tested, because it is the most energetic milling process of all.