One step production of aluminium matrix composite powders by mechanical alloying

Mechanical alloying technique has been used to produce aluminium-based metal matrix composite powders. As base material, the aluminium alloy AA2014 was selected, and two different carbides (VC and TiC) were chosen as reinforcements. Elemental powders (Al, Mg, Si and Cu) and carbide powders were mixed together in a high energy horizontal ball mill (Zoz attritor), with a balls/load (in weight) ratio of 20/1 at 700 rpm for different times (5, 7 and 10 h). The amount of elemental powders was such that the composition of AA2014 alloy (4.4% Cu, 0.5% Mg, 0.7% Si, Al bal., all wt.%) reinforced with 5%vol carbide powders was obtained. The produced composite powders were consequently analysed. The influence of the mechanical alloying parameters on morphology, particle size, microhardness, and microstructure of the final powder was studied. Results show that composite powders can be obtained in an only step with improved properties by means of mechanical alloying. The use of this technique and these powders as raw materials not only eliminates problems associated to other techniques of the MMC production but allows the achievement of materials with enhanced final properties due to a better powder production.