Numerical Study of SPIF Process of Al–Cu Bimetal Sheet Using Finite Element Analysis: Influence of Process Parameters on the Mechanical and Geometrical Responses

Abstract

Single point incremental forming (SPIF) which does not require any high capacity press machine nor a set of dies with specific shape, is an emerging sheet metal forming technology, capable of manufacturing complex parts at low cost for small to medium-batch production. This method is explained by the small plastic deformation caused by the force applied by a small punch on a sheet. The main reason to carry out such a process is to take the advantages of materials with different properties, such as high strength, low density, low price, and corrosion resistibility, at the same time and in a single component. The usage, of bimetal sheet is also justified because of the combination of the advantages offered by both materials of which it is composed and to a reduction of the disadvantages presented by each material if taken separately. The study presented in this research paper concerns a numerical investigation conducted on the incremental sheet metal forming process of Al and Cu bimetal composite. The finite element (FE) model validation was performed to compare the results obtained from the numerical simulations with experimental data available in the literature. The effects of process factors, which are considered as input parameters, such as: the tool diameter, wall inclination angle and layer arrangement, were investigated with finite element method (FEM) approaches on the forming time (the required time to forming the sheet), forming forces (the required forces to form the sheets), dimensional accuracy and maximum thickness variation (the maximum difference between initial thickness and formed sample thickness) of a truncated pyramid. The composite sheet behavior in a forming process differs from single-layer sheets and depends on the layers arrangement (contacted layer with the tool) and thickness. In this regard, the effect of layers arrangement on the forming behavior of (Al/Cu) bimetal sheet is of particular interest in the present study. Therefore, several tests were conducted to investigate the influences of some other variables, such as layers arrangement on the formability of the sheet material in a single point incremental forming process and the variations of force versus time diagram, defined as outputs.