Effect of Hydroforming Drawing Cups on Thickness Variation and Surface Roughness

Abstract

Recently, hydroforming was developed to address the emerging problems encountered by the conventional rigid tool-based deep drawing process. Hydroforming is a specialized type of die forming process, that uses a rigid die while the pressure provided by the liquid acts as a punch to shape the sheet metal. The current paper is directed to study the hydroforming process numerically and experimentally as a means for shaping aluminum alloy sheets based on the quality of product thickness variation and surface roughness. Moreover, it offered a comparative investigation of the experimental and numerical findings of this process. Therefore, thickness variation has been calculated numerically by designing a numerical model using Marc software which fits in large deformation simulation. On the other hand, thickness variation and surface roughness were measured experimentally along drawn cups and compared with the numerical results. The numerical results of thickness variation are matched with the experimental results. Furthermore, surface roughness was measured and compared before and after drawing at five regions. Since there is no contact between the upper side of a cup and any metallic parts, surface roughness depends only on the effect of plastic strain and was found to be increased in all regions.