Application of Taguchi Method to Investigate the Effect of Some Factors on In-Situ Formed Flake Structures of AL/ALB 2 Composite

A new in-situ metal matrix composite has been produced by liquid state reaction between aluminium and boron. The common boride phases obtained from this reaction are AlB 12 and AlB 2 of which the latter is stable at room temperature. One of the critical parameters of the reinforcement is the aspect ratio of AlB 2 flakes. In this study, the Taguchi design method has been employed to examine the effects of three process parameters of additive elements to Al matrix, cooling rate in the AlB 12 (solid) + Al(liquid) region, and cooling regime in the AlB 2(solid) + Al (liquid) region on the size of AlB 2 flakes. In the experiments, melting, casting, solidification, metallographic techniques, optical microscope, SEM and wet analysis techniques have been used. Results showed that 1.3 wt % boron has been dissolved in the aluminium at 1400 °C by adding boron oxide (B 2 O 3 ) resulting in AlB2 flakes of 2.5 % by volume. It is also concluded that the AlB 12(solid) + Al (liquid) region has to be passed with adequately high cooling rates in order to obtain AlB2 flakes with highest possible aspect ratios.