TOLLEY Alfredo Juan
congresos y reuniones científicas
Plastic deformation effect on the precipitation Al-Ge and Al-Cu-Si-Ge alloys.
M. V. CASTRO RIGLOS; A. TOLLEY; VELIMIR RADMILOVIC
Jornada; Jornadas SAM/CONAMET 2007; 2007
The addition of small amounts (about 0,5 at. %) of alloying elements like Si and Ge into Al-4%at.Cu age hardenable alloy makes the maximum hardness condition (?peak aging?) to appear earlier and provides a higher resistance on overageing. This effect is due to a very high density of Si-Ge precipitates with cubic-diamond structure that promote the heterogeneous precipitation of q´ Al2Cu phase. The issue of the present work is to show the first results on evaluating the influence of a plastic deformation (applied before artificial aging) on the mechanical properties of Al-Cu allied with Si-Ge. Initially, it was studied the influence of plastic deformation over hardness and microstructure for the Al-1%atGe binary alloy. It was observed that, for the same artficial aging time, the previously deformed specimens had a slight increment in their Vickers hardness, with respect to the undeformed specimens. The deformation applied was of 8% and the heat treatments were performed at 160ºC. On the other hand, the microstructure was characterized by means of transmission electron microscopy (TEM) on both kind of specimens (deformed and undeformed) and later compared. All this procedure was also carried out for Al-2%at Cu-0,5%at Si-0,5%at Ge specimens obtaining that the peak ageing appeared ahead for the previously deformed specimens.