INFLUENCE OF MATRIX ALLOYING ELEMENTS ON REACTIVE SYNTHESIS OF 2124-ALUMINUM-ALLOY METAL-MATRIX COMPOSITES

In situ TiB2 particle reinforced Al alloys are produced by reactive sy nthesis from elemental and prealloyed powders. The influence of 2124 a lloying elements on the reactive synthesis is evaluated with a compari son of elemental Al, elemental Al-Cu mixture, and 2124 Al prealloyed p owders as matrix materials. Experimental investigations by differentia l scanning calorimetry and dilatometry showed that the presence of Cu leads to an increase in the reaction rate during the formation of inte rmediate reaction products in comparison with the elemental Al matrix. X-ray diffraction of the reaction products showed a more complete con version of the intermediate Al3Ti as a result of Cu addition. The Cu h as no influence on the TiB2 particle size, but the TiB2 morphology cha nged from pure hexagonal to a more rounded morphology. MST/4038