Emerging Trends in Single Point Incremental Sheet Forming of Lightweight Metals

Sherwan Mohammed Najm,Tomasz Trzepieciński,Imre Paniti,Kuntal Maji,Tomaž Pepelnjak,Valentin Oleksik

doi:10.3390/met11081188

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.

Highlights

Nowadays, many sectors of industry use conventional sheet metal-forming (SMF) processes, such as stamping and deep drawing, to manufacture sheet metal components with high productivity [1]
Tool size is an essential factor that affects the properties of single point incremental forming (SPIF) components, since increasing the tool diameter causes a decrease in the hardness of AA1100 aluminium [63], whereas decreasing it causes higher formability and a lowering of the forming force of a commercially pure titanium (CP-Ti) sheet [64]
Directions This article provides an overview of aspects of current research on SPIF of lightweight materials technology

Summary

Introduction

Many sectors of industry use conventional sheet metal-forming (SMF) processes, such as stamping and deep drawing, to manufacture sheet metal components with high productivity [1]. There are many research studies dealing with the forming of components made of steel sheets and deformable copper and aluminium alloys These processes do not require special technological treatments, and they are usually carried out in cold working conditions. Tool size is an essential factor that affects the properties of SPIF components, since increasing the tool diameter causes a decrease in the hardness of AA1100 aluminium [63], whereas decreasing it causes higher formability and a lowering of the forming force of a commercially pure titanium (CP-Ti) sheet [64]. Uheida et al [79] studied the influence of tool velocity on the process conditions in SPIF of grade 2 titanium sheets They alleged that increasing the forming temperature and forming force are directly linked to the tool rotation speed, and that this is the critical factor that drove the thermomechanical effects. As the radius of the tool increases, the minimum thickness increases due to an increase in the contact area between the tool and the sheet

Forming Forces

Deformation Mechanism

Heat-Assisted Formability

Air-Assisted Heating

Summary of Findings

Toolpath and Toolpath Strategies

Lubricants

Determination of COF

Robotisation in ISF

10. Emerging Incremental Forming Methods

11. Conclusions and Future Directions

Findings