TEM Observation of Cu and Ag Added Al-Mg-Si Alloy

THREE DIMENSIONAL ATOM PROBE ANALYSIS OF PRE-PRECIPITATE CLUSTERING IN AN Al-Cu-Mg-Ag ALLOY

Trace element additions in age hardening aluminum alloys often modify precipitation products and kinetics. In the case of Al-Cu alloy, combined addition of trace amount of Mg and Ag leads to precipitation of fine and uniform dispersions of plate-like Ω phase on the {111}Al planes in addition to the θ′ precipitates on the {001}Al planes [1,2]. The Ω phase shows high thermal stability and resista...

DISLOCATION INTERACTION WITH SEMICOHERENT PRECIPITATES (O PHASE) IN DEFORMED Al±Cu±Mg±Ag ALLOY

ÐThe interaction between dislocations and semicoherent precipitates (O phase) is discussed. The investigation shows that the semicoherent precipitate is cut by dislocations during deformation. Conventional TEM and HRTEM observations demonstrate that shearing of precipitates by dislocations occurs by multiple cutting of the precipitate. A strengthening mechanism is proposed based on this observa...

CORROSION BEHAVIOUR OF Al-Li-Cu-Mg ALLOY 8090-T651

The Effect of Cu Additions on the Precipitation Kinetics in an Al-Mg-Si Alloy with Excess Si

The microstructural evolution during age hardening of a Cu-bearing Al-Mg-Si alloy has been investigated by the three-dimensional atom probe (3DAP) and transmission electron microscope (TEM) techniques, in order to clarify the effect of Cu on the initial age-hardening response. After 30 minutes of artificial aging at 175 8C, the alloy shows a significant increase in hardness. The TEM observation...

Clustering and Segregation of Mg and Ag Atoms during the Precipitation Processes in Al(-Li)-Cu-Mg-Ag Alloys

This paper reports three dimensional atom probe (3DAP) results of solute clusters and precipitates in early aging stages of Al-Cu(-Li) alloys containing small amounts of Ag and Mg atoms. In an as-quenched Al-1.9Cu-0.3Mg-0.2Ag (at.%) alloy, solute atoms are uniformly dissolved. On aging for 5 s at 180°C, Ag and Mg atoms form co-clusters. These co-clusters do not have well defined shape, but they...