The experimental investigation of springback and roughness parameters in the three-point forming process using terpolymer punch

Abstract

By the application of the three-point metal forming process, copious shapes can be formed. While doing the forming process, various unavoidable sheet metal defects will occur. This paper predominantly emphasizes springback and roughness defects and investigates the effects of these parameters with terpolymer Acrylonitrile Butadiene Styrene (ABS) fiber tool punch. Low-cost tooling and quality part development benefit from fiber tool punch over traditional steel tool punch. The springback and surface roughness are analyzed in the AA6061 sheet using steel and fiber punch in three-point U-bending operations, which are carried out as per ASTM standards. For this purpose, steel and fiber punch with nose diameters of 4, 8, and 12 mm and sheet metals of thicknesses 1 and 2 mm are used. The 8%–10% reduction in springback is achieved in fiber punch than steel punch. Also, the fiber punch offers 10%–47%better surface roughness than the steel punch. As the diameter of the punch increases, the roughness value also increases irrespective of the punch material. The fiber – reinforced ABS punch presents an attractive opportunity to reduce the springback effect and improve the surface quality of the finished product.