Numerical Investigation of Dieless Incremental Forming Technology of Low Carbon Steel-CP Titanium Bilayer Composite Plate: Impact of Input Factors on Mechanical and Geometrical Characteristics

The application of single point incremental forming process (SPIF) on a composite is an innovative and emergent engineering method that has attracted particular attention due to its flexibility. It can combine the benefits from process and material to achieve high level of formability and deformation behavior of incrementally formed parts. In this regard, the incremental forming of CP-titanium/low-carbon steel bimetallic sheets has been investigated in this article both experimentally and numerically. To achieve this, a finite element analysis was conducted. Juxtaposition between experimental results and numerical ones was done. The comparison shows a good agreement. In fact, the influence of certain variables of the process was clarified. The input variables of the numerical model included the layer arrangement, the sheet material thickness, the drawing angle, and the vertical step down. The forming behavior of bimetallic composite sheets was investigated according to those factors. The impact of those SPIF parameters on both loading resulting from forming operation and thickness evolution was determined. The results have shown that the deformation mechanism in this sheet composite may differ from the deformation behavior of homogeneous metal sheets, which depends on the layer arrangements and mechanical properties of each. Also, the different findings confirm that the yielding starts from the upper stacking layer directly contacting the tool. The outer surface is deformed according to the inner surface deformation of the truncated pyramid frustum. Furthermore, this study demonstrates a remarkable influence of these considered process parameters: the layer arrangements and other input variables, simultaneously on the mechanical and the geometrical responses.