Evaluation of ZrB2 reinforced Al/Al alloy composite produced by powder metallurgy-vacuum arc melting technique: A unique approach

In the present study, the Al/Al alloy reinforced with ZrB2 composite is produced by the combination of powder metallurgy (PM) and Vacuum arc melting (VAM) techniques. The composite powder is milled for homogenous composition and uniaxially cold compacted to form green compacts which are used as raw materials in VAM. The composites are remelted by tumbling the melts after completion of each melt to ensure homogenous composition. The composites are then ground to the core of the melt and metallographically mirror surface finished to examine the microstructure. Secondary phase CuAl2 precipitates are formed due to the alloying effect between Cu and Al. The ZrB2 reinforcement particles existed in groups along the grain boundaries and sparsely in the bulk of the composite. The hardness increased with the alloying effect and also with the addition of ZrB2 reinforcement particles. The corrosion rate of the composite was evaluated by potentiodynamic polarization study. Corrosion rate increased with the presence of secondary phase particles.