Influence of matrix alloying elements on reactive synthesis of 2124 aluminium alloy metal matrix composites

In situ TiB2particle reinforced Al alloys are produced by reactive synthesis from elemental and prealloyed powders. The influence of 2124 alloying elements on the reactive synthesis is evaluated with a comparison of elemental AI, elemental AI-Cu mixture, and 2124 Al prealloyed powders as matrix materials. Experimental investigations by differential scanning calorimetry and dilatometry showed that the presence of Cu leads to an increase in the reaction rate during the formation of intermediate reaction products in comparison with the elemental Al matrix. X-ray diffraction of the reaction products showed a more complete conversion of the intermediate Al3Ti as a result of Cu addition. The Cu has no influence on the TiB2particle size, but the TiB2morphology changed from pure hexagonal to a more rounded morphology.