Emerging Trends in Single Point Incremental Sheet Forming of Lightweight Metals

Abstract

Lightweight materials, such as titanium alloys, magnesium alloys, and aluminium alloys, are characterised by unusual combinations of high strength, corrosion resistance, and low weight. However, some of the grades of these alloys exhibit poor formability at room temperature, which limits their application in sheet metal-forming processes. Lightweight materials are used extensively in the automobile and aerospace industries, leading to increasing demands for advanced forming technologies. This article presents a brief overview of state-of-the-art methods of incremental sheet forming (ISF) for lightweight materials with a special emphasis on the research published in 2015–2021. First, a review of the incremental forming method is provided. Next, the effect of the process conditions (i.e., forming tool, forming path, forming parameters) on the surface finish of drawpieces, geometric accuracy, and process formability of the sheet metals in conventional ISF and thermally-assisted ISF variants are considered. Special attention is given to a review of the effects of contact conditions between the tool and sheet metal on material deformation. The previous publications related to emerging incremental forming technologies, i.e., laser-assisted ISF, water jet ISF, electrically-assisted ISF and ultrasonic-assisted ISF, are also reviewed. The paper seeks to guide and inspire researchers by identifying the current development trends of the valuable contributions made in the field of SPIF of lightweight metallic materials.

Single-Point Incremental Forming of Titanium and Titanium Alloy Sheets

“…The hot incremental forming process provides the opportunity to improve the formability of Ti alloys [ 33 ]. It is almost impossible to plastic-form Ti alloys at room temperature because of the hexagonal close packed structure of the alpha phase and major plastic deformation by twinning [ 82 ].…”

“…SPIF and TPIF of titanium alloys have specific properties, the knowledge of which is necessary for the proper management of the process. Recent development trends in sheet metal forming and SPIF of lightweight metals have been provided by Trzepieciński et al [ 33 , 34 ].…”

Multistage Tool Path Optimisation of Single-Point Incremental Forming Process

“…This suggests that the models accurately describe the relationship between the input parameters and the outputs. The two models are functions of the vertical step-down sizes during the first forming stage (∆z1), the second forming stage (∆z2) and the depth during the first forming stage (h), see Equation (10).…”

“…The genetic algorithm is a search optimisation technique that is inspired by natural evolution. The geometrical deviation and forming time shown in Equation (10) and the corresponding constants listed in Table 3 were simultaneously solved, and the contour plot of the optimisation is shown in Figure 9. The model shows that the optimum values of the vertical increment of stage 1, vertical increment of stage 2 and the depth of forming stage 1 would be 4.5, 1.59 and 39 mm, respectively.…”

“…The SPIF process can reduce production costs by eliminating the need for die manufacturing. It also offers a high degree of flexibility in customisation, especially for medium-sized production, resulting in die-less metal forming [10]. Single-point incremental forming is based on the conventional sheet metal spinning commonly used for the production of axisymmetric shape complex parts, without the need for using dies [11][12][13].…”