The aluminum are in as rolled and as extruded condition. What I am trying to accomplish is to relieve the residual stress from the welding shrinkage. It is the residual stress coupled with the thermal stress causing the welds to crack.
As to your second question, of course there could be micro...
We have an aluminum welded structure consisting of .38 6061 plate with 3x3x.38 angles on one side for stiffness. This assembly will typically be used as part of a mold in an oven operating at 415°F for 3 hours, then cooling for an hour to about 300°F. At this point it is taken out an air cooled...