Production of Al4C3 phase from carbon and AA2014 alloy powders by means of solid phase reaction technique and its effect on ageing

At the beginning of this work, powders of AA 2014 alloy were manufactured by the use of gas atomization technique, where the final powder size was found to be 95,43 µm on the average. There after, alloy powders, were first mixed with 2% graphite and 0.5% zinc stearate aggregate and then synthesized by means of Mechanical Alloying (MA). The process was performed in a gas tight vertical attritor at most for 8 hours, where running speed was approximately 500 rpm, and ball to powder ratio was fixed to be 20 : 1. After verifying the mean partical size of the synthesized product, powders were first cold pressed at about 800 MPa, and later sintered at 550 ºC (for 2-24 hours) and 600 ºC (for about 2?196 hours) in argon atmosphere, respectively.Hardness values of all samples were measured and then analysed by means of XRD and Energy Dispersive Spectrometry (EDS). In this way, first the presence of the Al4C3 phase was verified, and later the effect of the duration of prolonged annnealing and change in tempereture on the amount of Al4C3 phase was determined. Also, how the presence of Al4C3 phase affects the optimum strength of the material was measured. Further, optical microscopy and electron microscopy (SEM) techniques were used to study the micro-structural features of the samples.As a final treatment, all samples were age hardened, where the additional strength available from the presence of Al4C3 phase was verified. It was found that after aging, the strength of this new AA2014 material tends to increase substantially.