IN-SITU TRANSMISSION ELECTRON-MICROSCOPY STUDY OF PLASTIC-DEFORMATIONIN PASSIVATED AL-CU THIN-FILMS

Plastic deformation in passivated Al-1 wt %Cu thin films was studied i n situ using a straining device in the transmission electron microscop e. Both edge and screw dislocations were found to have caused slip on inclined {111} planes. Multiple slip was frequently observed as two or more sets of intersecting slip traces. Microstructural investigations of both unpassivated and passivated Al-1 wt %Cu films indicate that g rain size and encapsulation by passivating layers are major contributo rs to strength of a thin film with a particular thickness. Additional strengthening is also provided by interactions between dislocations on multiple slip systems. The roles of grain orientation and precipitate s in plastic deformation are also discussed. (C) 1997 American Institu te of Physics.