Formability and failure modes in Single Point Incremental Forming of Metal-Polymer Laminates

Single Point Incremental Forming (SPIF) is a sheet forming technique with several advantages compared to conventional sheet forming including low-cost and part-shape-independent tooling, and higher process flexibility. While recent work has demonstrated the feasibility of SPIF of metal-polymer-metal sandwich sheets, the effects of SPIF process parameters on formability have rarely been examined. This work examines how incremental depth, metal thickness and polymer thickness affect formability and failure modes during SPIF of adhesively bonded metal-polymer laminate sheets. It is shown that higher polymer thickness results in higher formability, but this advantage is limited by the occurrence of metal tearing and galling. Further, the mode of failure is found to depend on the metal sheet thickness and polymer sheet thickness. In laminates with thinner metal sheet only two modes of failure, delamination and metal tearing occur. In laminates with thick metal sheet galling of the polymer is also observed, in addition to the above failure modes. (C) 2018 The Authors. Published by Elsevier B.V.