Enhancement of process capabilities in electrically-assisted double sided incremental forming

Abstract

Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/) eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. (2016) Materials and Design 92 Abstract Electrically-assisted incremental sheet forming (E-ISF) is an effective method to improve materialformability by introducing the electric current in ISF process. This method is particularly useful for fabrication of conventional lightweight 'hard-to-form' materials such as magnesium and titanium alloys. However, the use of electricity and heat in the forming process may also introduce side effects to formed components, such as unsatisfied surface finish. In this work, an improved E-DSIF process has been developed by combining the double sided incremental forming (DSIF) and the electrically-assisted forming technology. Different types of forming tools and toolpath strategies are explored to improve surface finish and geometrical accuracy based on a customized DSIF machine. AZ31B magnesium alloy sheets are formed into a truncated cone shape to verify the proposed approaches. According to the comparative studies, the causes of the rough surface finish in the conventional E-ISF process are investigated, and the surface finish is refined by improving the contact condition at tool-sheet interface in the newly developed process. In addition, a hybrid toolpath strategy is proposed to further enhance the geometrical accuracy. The work demonstrates that the two challenging issues in the E-ISF process, surface finish and geometrical accuracy, could be improved by using the enhanced technologies.

Incremental Forming of Titanium Ti6Al4V Alloy for Cranioplasty Plates—Decision-Making Process and Technological Approaches

“…A master-slave tool layout for double-side incremental forming (DSIF) combined with electrically assisted heating was presented in [26]. Good results were reported in processing lightweight materials (AZ31B magnesium alloy) with regards to surface quality and maximum wall angle for truncated cone parts and a new type of hybrid toolpath lead to better geometric accuracy.…”

A hybrid mixed double-sided incremental forming method for forming Ti6Al4V alloy

“…In ISF, the periphery of the sheet metal is clamped, while the material is locally deformed by one, i.e., Single Point Incremental Forming (SPIF), or more stylus tools that move along pre-defined toolpaths. Therefore, because of their dieless nature and high flexibility, these techniques are most suitable when low-volume customized sheet metal parts, as the case of biomedical implants, have to be manufactured [3].…”

“…One challenge in all the above incremental forming techniques is forming workpieces made of lightweight but difficult-to-form materials [3], such as Ti6Al4V. Because of its limited formability at room temperature [9], a possible solution to form Ti6Al4V sheets using ISF processes is to increase the forming temperature.…”

Investigation of Heterogeneous Joule Heating as the Explanation for the Transient Electroplastic Stress Drop in Pulsed Tension of 7075-T6 Aluminum

“…In order to drive the model to predict the observed stress drop, the bulk temperature of the specimen exceeds experiment, while the dislocation density and grain boundary electrical resistivity exceed published values, thereby suggesting that microscale heterogeneous heating theory is not the full explanation for the transient electroplastic effect. A new theory for explaining the electroplastic effect based on dissolution of bonds is proposed called the Electron Stagnation Theory.The effect of electricity on metals during deformation, known as the electroplastic effect, can be utilized to reduce forming loads, springback, and flow stress while increasing ductility during various forming processes [1][2][3][4][5][6][7]. A review of the impact of electricity on various manufacturing processes is reported in Ref.…”

“…The effect of electricity on metals during deformation, known as the electroplastic effect, can be utilized to reduce forming loads, springback, and flow stress while increasing ductility during various forming processes [1][2][3][4][5][6][7]. A review of the impact of electricity on various manufacturing processes is reported in Ref.…”