Reduction of friction in deep drawing of aluminium alloys by generating local hydrostatic-pressure lubrication

A new technology has been developed to optimize the aluminium sheet forming process concerning forming limits and adhesive wear. In this method, a lubricant is pumped through openings into the forming zone at the local area of highest contact normal stresses. A hydrostatic pressure lubrication built up in this area and resulted in a clear reduction of the local friction forces. In a strip-drawing test a significant reduction of the total drawing force occured. The position of the openings had a major influence, and this is investigated experimentally and with the aid of finite element analysis.