The structure and formation of dislocation networks in aluminium-magnesium alloys

When investigating rapidly solidified aluminium—magnesium alloys by means of the thin foil technique, dislocation networks were abundantly revealed. It is shown that these are knitted on dislocation forests generated on contact boundaries of sub-dendrites or cells growing from the melt. Knitting occurs mainly by climb when ‘detached’ dislocations nucleating inside the cells during solidification and cooling are trapped by forests. Several reactions between detached and forest dislocations are analysed.