MICROSTRUCTURE OF TWO-PHASE Al-1.7 at/100 Cu ALLOY DEFORMED BY EQUAL-CHANNEL ANGULAR PRESSING

摘要

The microstructural changes of an aged Al-l.7 at/100 Cu alloy associated with severe plastic defor- mation have been studied by transmission electron microscopy (TEM) and energy-filtered transmission elec- tron microscopy (EF-TEM). precipitates are almost completely dissolved after eight passes of equal- channel angular (ECA) pressing, and nearly single-phase α with a fine grain size of approximately 500 nm is obtained. when a severely deformed sample is aged for 24 h at 100deg.c, precipitation of equiaxed θ Phase is observed along the grain boundaries, whereas only Guinier-Preston (GP) zones are formed in the unde- formed sample. The dissolution and precipitation processes in severely deformed Al-l.7 at/100 Cu alloy have been examined by TEM and energy-filter mapping.