INFLUENCE OF VARIOUS ROLLING CONDITIONS AND FINE SURFACE STRUCTURE ON THE DEEP-DRAWING BEHAVIOUR OF ALUMINIUM SHEET.

Various processing difficulties arise in the deep-drawing of aluminum sheet. The intention of the present investigation was to determine the microsurface characteristics and lubrication conditions that promise optimum processing conditions. Tests showed that for the alloys considered, a temper-pass reduction of 6 to 7% was particularly effective in producing a suitable microsurface structure. A microsurface produced in this way at the final stage with AlMg4 and AlMg0. 4Si1. 2 sheet resulted in an improvement of the deep-drawing properties (differential force) by 10%. An unexpectedly large improvement of approximately 35% in the deep-drawing properties is obtained with both alloys when, after producing the microsurface in question, additional heat treatment is carried out. This improvement is given by a microsurface of suitable, non-directional structure, with an amount of lubricant unusually small by today's standards.