Forming tools having textured surfaces

A forming tool for shaping a metal blank into a desired shape, comprising:

• a contoured die surface for pressing against the metal blank so that respective portions of the metal blank flow over the contoured surface during deformation of the metal blank into the desired shape;
• wherein the contoured die surface corresponds to an intrinsic material flow pattern based on a uniform coefficient of resistance across the contoured die surface that would cause unequal stretching of the metal blank, so that an insufficient flow in the predetermined regions would create areas in the shaped metal blank receiving less than a desired amount of metal;
• and
• wherein the contoured surface carries a surface texture in a pattern that increases metal flow along the predetermined regions, whereby a reduced coefficient of friction is provided in the predetermined regions relative to a coefficient of friction of the contoured surface adjacent to the predetermined regions;
• wherein the surface texture is comprised of laser etched dimples, wherein the dimples are formed as raised features above the contoured surface, and wherein each dimple is in a range of about 5-10 μm in length and about 3 μm in height;
• wherein the laser etched dimples are comprised of elliptical dimples having an aspect ratio not equal to one and having a major axis and a minor axis;
• wherein the metal flow encounters a lowest flow resistance along the minor axis;
• and
• wherein the elliptical dimples have their respective minor axis aligned with respective desired flow directions in the predetermined regions.