STRUCTURE AND MOBILITY OF POLYGONIZED DISLOCATION WALLS IN HIGH-PURITY ALUMINUM

In this work, we characterize the different polygonized walls appearin g in 6N Al (99.9999% pure) and in 5N Al (99.999% pure) after creep. We observe that these sub-boundaries are usually composed of three or fi ve dislocation families. However, special attention is devoted to stud y of the polygonized sub-boundaries with five dislocation families. In order to study the mobility of these sub-boundaries, we analyse the d islocation families of which they are composed and their possible mobi lity. In addition, the studies done using anelastic techniques on samp les with different microstructures (tangled dislocations or polygonize d sub-boundaries) allow us to attribute the internal friction peak P(H T) to the movement of sub-boundaries by a combination of a climb mecha nism and a glide mechanism on non-compact planes.