Numerical Investigation of the Influence of some Parameters in SPIF Process on the Forming Forces and Thickness Distributions of a Bimetallic Sheet CP-Titanium/Low-carbon Steel Compared to an Individual Layer

摘要

The single point incremental forming process (SPIF) of sheet metal is an emerging manufacturing process which still in progress. It is well-known to be perfectly suited for prototyping and small series. However, this process is not really industrialized yet, mainly due its geometrical inaccuracy, its non-homogeneous thickness distribution... Moreover, considerable forces can occur. They must be controlled in order to preserve the tooling. For this purpose, many different research studies were conducted in order to investigate its different aspects. The application of single point incremental forming to bimetallic composite sheet is recently examined. Preliminarily results are promising further investigations. In the present paper, authors have tried to check the feasibility of the SPIF process by establishing a comparative study between the composite bilayer sheet behavior low-carbon steel/commercially pure titanium (St/CP-Ti) in forming process and the forming behavior of a single layer sheet made of CP-Titanium. The effect of process parameters such as the vertical step size of the tool path, the initial sheet thickness and the wall angle inclination of a truncated pyramid were investigated with finite element method (FEM) approach on the forming forces and the thickness distributions. In other words, a numerical analysis is conducted in order to predict the forming forces and the homogeneity of the thickness variations of bilayer material compared to the single layer sheet. Finally, this study reveals the importance of the bilayer sheet as a low-cost material. In addition, it elucidates the flexibility of SPIF process to deform composite sheet.