Review of Recent Development in Deep Drawing Process
Deep drawing is a common metal forming process used to manufacture recessed threedimensional parts from flat sheet metals. The research in deep drawing has been generic over the last few decades and various aspects of this process have been investigated. The paper aims to review the following aspects of deep drawing process that affect the quality of the product, tooling life and process design: i. The development of a theoretical model for the isoviscous hydrodynamic lubrication of deep drawing and its comparison with experimental results, the effect of lubrication on die expansion that could be used as an indirect means of detecting and measuring the presence of a hydrodynamic lubricant film thickness. ii. The improvement in deep drawing tooling that covers analysis for the blank holder, the effect of punch geometry on the deep drawing process, and introducing an alternative tooling materials for batch production. iii. The recent developments and future direction of research.
Design considerations for hydromechanical deep drawing of sheet components with concave features
Abstract Design for hydromechanical deep drawing of sheet components with concave features requires more detailed considerations than that for the forming of components with convex features. FE simulations were conducted to examine the deformation of the sheet during the forming of these component-forms and to qualify the influence of counter-pressure paths on the product-quality, with a view to developing a reference for process, tool and component design considerations for the hydromechanical drawing of such component-forms. The results suggested that in order to prevent the initiation of forming-defects and to achieve high-quality products, the counter-pressure paths should be designed to match the component-forms to be produced.
A Study of the Lubrication Mechanisms in Deep Drawing
The oil film thicknesses between the tools and the workpiece and their changes during a cup drawing operation are analytically predicted to facilitate estimating the effects of the process variables on the lubricating conditions, including the blank holding speed, the time elapsed after setting the blank holder until the beginning of the punch penetration, drawing speed, lubricant viscosity, blank material and the geometries of tools and workpiece. It is experimentally shown that the greater is the ratio of the calculated oil film thickness to the maximum surface roughness which would result on the deforming workpiece separated from the tool by a very thick oil film, the smaller are the contact ratio and the friction between the tool and workpiece. The experiment also shows significant changes in the lubricating conditions on the die flat and on the die profile during the process.