Additional-Element Effects on the Ageing Phenomena in Al-4% Cu Alloys

A. Q. Khan
1972 Transactions of the Japan Institute of Metals  
Starting from the hypothesis(1) that elements with low solubility in Al have higher binding energies with vacancies than copper atoms and(2) that the size of the added element could affect the precipitation behaviour, a number of elements,viz.Pb , Cd, W, Be, Na and Ge were added to an Al-4% Cu alloy. The ageing process was studied by means of hardness measurements, X-ray analysis and electron microscopy. Preliminary experiments showed that Pb, W, Na and Ge did not have any effect and were thus
more » ... iscarded. While the elements Pb, W and Na were inactive probably because of their insolubility in Al, it was concluded that the binding energy of Ge-vacancy was much lower than reported in literature. Be, Cd and Be+Cd showed pronounced effects on the ageing characteristics of the binary alloy. The effect of Be on the quenched Al-4%Cu alloy egad at 220℃ differed from that of Cd.
doi:10.2320/matertrans1960.13.149 fatcat:x5ktd5f6zvcj3nnhx4ugkfnmcu