An investigation of liquid metal lubrication during electrically-assisted incremental forming of titanium

Incremental Forming (IF) is a sheet material forming process that does not require the use of dedicated dies. This is accomplished through local deformations made with a forming tool. Many improvements towards the IF process are categorized into the following categories: formability, springback, surface finish, and forming forces. The addition of an electrical current to the IF process has been investigated and shown to significantly reduce springback and forming force and increase formability. Current is often applied by assigning the forming tool to be an electrode and passing the current through the workpiece to the clamping fixture. While this configuration represents a simple, yet effective solution, its main drawback is a significant degradation of the surface, resulting from spatting of the tool. Herein, the utilization of a highly conductive liquid metal is investigated for its use as a conductive medium, as well as a lubricant, in the electrically assisted incremental forming process. It was determined that this lubricant is able to improve formability and surface finish over conventional MoS2 lubricant while significantly reducing springback. (C) 2019 The Authors. Published by Elsevier B.V.