Optimized Design of Deep Drawing Machines for Aluminium
In forming of steel sheets the useful deformation capacity is extended well beyond the uniform elongation into the range of fracture elongation (necking). When forming aluminium sheet metal parts deformation should be confined to the region of uniform elongation and the region of necking should be avoided. For aluminium alloys it is important to work with prototype tools to determine the feasibility of drawing as well as the springback effect. In addition, it is helpful to ascertain the tolerances which can be attained by altering the tools. Some general recommendations should be remembered when designing press tools for the successful drawing of aluminium parts, see Figure 3704.01.10. Special attention should be given to the subject of lubrication. The aluminium industry offers aluminium sheets with a wide range of surface morphologies, including sheet surfaces with spark eroded textures (EDT) which allow a good distribution of lubricant, thus making it possible to obtain better performances with acceptable surfaces for difficult forming operations [Ref. 5 and TALAT Lecture 3702].