Production of functionally graded AlB2/Al-4%Mg composite by centrifugal casting

Abstract

In this study, production of functionally graded AlB₂ reinforced Al-4%Mg composite has been investigated. In-situ high-aspect-ratio flake AlB₂ reinforcement was obtained by the addition of boron oxide to the liquid Al-Mg at 1400 °C. It has been observed that there were two distinct regions without a smooth grading: one is rich of and the other is poor of AlB₂. The results showed that the highest AlB₂ content has been found to be around 10% in external zones, whereas the lowest AlB₂ content has been observed to be 0.02% in the internal zones.  Additionally,   results showed that, depending on the increase in the reinforcement phase in external zones, up to 20 % increase in the hardness of the composite has been achieved.