Formability of AA7075 Sheet in Single Point Incremental Forming

1. Introduction

Incremental sheet forming (ISF) is a relatively new forming process in which localized deformation takes place on clamped sheet metal gradually according to predefined tool-path. Enhanced formability compared to conventional forming, and flexible process of ISF makes it suitable to manufacture sheet metallic parts for various industrial applications. It is a cost-effective forming process because it does not require a dedicated tool, forming press and dies. ISF process is suitable for rapid prototyping and small-batch production (Duflou et al. (2018), Li et al. (2017), McAnulty et al. (2017)). Aluminium alloy of 7xxx series is widely used to make the different structural components of automotive and aircraft due to its good ductility, high strength, and low density (Liu et al. (2013), Djavanroodi et al. (2019)). AA7075 with zinc as a major alloying element is one of the strongest aluminium alloys which is widely used in industries because of its high strength and low weight, together with its natural ageing characteristics. Due to such properties, it is suitable for several structural applications in automotive, aerospace, and other industries (Shojaeefard et al. (2013)). The capability of a sheet metal to what extent it can be successfully deformed without any necking or fracture in sheet metal forming is called as formability. Forming limit curve (FLC) is a widely used tool for formability prediction in sheet metal forming. FLC is a plot of major strain vs minor strain which shows the limit strains for sheet metal material (Isik et al. (2014), Duflou et al. (2018)).