Microstructure and mechanical behavior of high toughness Al-based metal matrix composite reinforced with in-situ formed nickel aluminides

A powder blend of Ni particles embedded in Al flakes obtained after high energy ball milling was used to reinforce an AlMg alloy using friction stir processing (FSP). The mechanical activation provided by both ball milling and FSP resulted in the in-situ formation of nickel aluminides during FSP, which was distributed throughout the nugget zone. The average grain size after FSP was 8.3 μm. High dislocation density was observed in the vicinity of...