Evaluation of sheet metal formability, viscous pressure forming (VPF) dome test

Viscous pressure forming (VPF): state-of-the-art and future trends

“…However, the punch gradually makes contact with the sheet metal and the friction force is then related only to the surface quality of sheet metal and the rigid punch. Comparing the thickness of parts formed by VPF, rigid punch forming and hydro-forming with the numerical simulation method, the thickness of parts obtained by VPF is more uniform than that by rigid punch forming and hydro-forming [7,8]. The numerical simulation method was used to analyze the influence of the tangential adhesive stress on the strain distribution and thickness distribution of the sheet metal in the VPF bulging process.…”

Effects of viscosity on viscous pressure bulging (VPB) of Al1060 sheet

“…Liu et al [11,12] simulated the stretching process with two different viscous mediums, C-21 (η=5000 Pa s) and C-11 (η=10,000 Pa s), finding that the wall thickness of parts obtained by using lowviscosity medium (C-21) was relatively uniform and no local necking was observed. Wang [13] presented compression experiments of three viscous mediums with different molecular weights (450,000, 500,000, and 550, 000 g/mol), the relationship curves between the flow stress and strain of these three kind of viscous medium were obtained, which provides an experimental basis for analyzing the mechanical properties of the viscous medium.…”

Formability of 6k21-T4 car panel sheet for viscoelastic–plastic flexible-die forming

“…Superplastic forming is also suitable for forming of complex and difficult-to-form outer panels such as the front wing outer panel of car of 5182 aluminum alloy (Zeng et al, 2005) The viscoelastic-plastic flexible-die forming uses the viscoelastic-plastic material as the forming flexible-die. The previous investigations show that the viscoelastic-plastic flexible-die forming can improve the sheet formability (Liu et al, 1996(Liu et al, , 2000(Liu et al, , 2003. The flexible-die material is a semi-solid, flexible, highly viscous and strain rate sensitive macromolecule polymer.…”