Analysis of hydro-mechanical deep drawing and the effects of cavity pressure on quality of simultaneously formed three-layer Al alloy parts

Abstract

Stamp forming method used for forming of relatively smaller and complex-shaped fiber metal laminate (FML) parts has inherent constraints such as fiber sheet rupture, metallic layers quantity, and repeated heating/ solidification of thermoplastic (TP) resin/tooling. As an alternate and efficient strategy, simultaneous forming of multiple blanks has been studied by using hydro-mechanical deep drawing (HDD) method. Also, the effect of process variables such as cavity pressure and blank holding force (BHF) and their role in wrinkles formation, thinning, edges movement and formability for the HDD process (performed with and without applying the cavity pressure) has been deliberated. Blanks made of Al 2024-O alloy sheet were used and the formability attributes, based on Barlat 2000 yield criteria, were estimated using DYNAFORM/LS-DYNA and compared with the experimental results. The results show that application of cavity pressure within certain limits has a positive effect on the quality of three-layer formed part as well as leads to higher depths as compared with the process when no cavity pressure was applied. Good agreement has been found between the predicted and the experimental results. The simultaneous forming strategy can give the advantage of eradicating the strict process controls which are needed in the conventional stamp forming method and can expand the application areas of FML parts for the aerospace and automobile industries.

Development of hot embossing stamps with conformal cooling channels for microreplication

“…Thus, optimization of conformal cooling channel designs in terms of location and cooling channel size can be further investigated using computer simulation software [27]. The hot embossing stamps have a limited life compared to conventional metal stamps [28][29][30][31]. In order to enhance lifespan of a hot embossing stamp, stamp surface with wear-resistant hard coatings is still required.…”

New Advances and Future Possibilities in Forming Technology of Hybrid Metal–Polymer Composites Used in Aerospace Applications

“…Recently, these forming methods were utilised to form steel-based FMLs, but the latest research papers have been focused mainly on aluminium-based composites. Researchers consider the configuration of the material layers [374][375][376][377] or the process parameter setup [86,[378][379][380][381][382][383][384][385][386] to reduce material defects and go beyond the current forming limits caused mainly by breakage and wrinkling. In order to improve the formability of the layers of FRP, many studies are focused on die forming at elevated temperatures [387][388][389].…”

“…An increase in the FRP layer thickness increases circumferential pressure causing initial buckling. Zafar et al [382] presented an alternative method of hydromechanical deep drawing to produce FML blanks. Stacks of three Al 2024-O discs, each 0.5 mm thick, were used in the experiment at room temperature.…”

Investigation on the Effect of Type of Cooling on the Properties of Aluminum Alloy during Warm/Hot Hydromechanical Deep Drawing

“…In addition, research shows that [5,11,12] assuming that the material is isotropy, stress-strain curves obtained by the bulging test have been very close to the actual flow properties of materials and can reflect the stress-strain state during the forming process. Considering that the cylindrical cups HDD experiment is a classic basic research method [13,14], it was used to research the effect of the process of warm/hot sheet hydroforming with subsequent rapid cooling on mechanical properties and microstructure evolution of the cups, which were formed by warm/hot sheet HDD [15,16]. Meanwhile, the isotropic material was assumed in this study.…”