# Springback Behavior of AA 7075-T6 Alloy in V-Shaped Bending
## 1 Introduction  
Aluminum alloys are frequently preferred due to their low densities, high strength properties, low ductility values, and good corrosion resistance. AI7 xxx series aluminum alloys are widely used in many vital areas of the industry due to their superior properties, such as automotive, defense, space, and aviation. However, various problems limit the shaping of these alloys using plastic forming methods. Low ductility and difficult formability at room temperature are among the factors that significantly restrict the formability of AI7075 material. To increase the forming capabilities of the AI7075 alloy, it is necessary to apply heat treatment before forming processes or to generate heat input during forming processes [1, 2, 3, 4, 5]. Sheet metal forming is a production method in many fields, such as the automotive, packaging, and home appliance industries. Bending is one of the most common processes among these production methods. The most significant problem in bending operations is springback. Springback can be defined as the elastic change in the form of a product when external loads are removed [6, 7, 8, 9, 10]. Numerous studies have focused on identifying the key factors influencing springback. These factors generally fall into two main categories: material characteristics and processing conditions. Material-related parameters include elastic modulus, yield strength, ultimate tensile strength, elongation capacity, strain hardening coefficient, plastic anisotropy, and sensitivity to strain rate. On the other hand, process-related variables encompass deformation speed, operating temperature, friction and lubrication levels, applied forming force, tool geometry and dimensions, and sheet thickness [11, 12, 13, 14, 15]. One particular study examined the influence of parameters like grain size, punch radius, and punching speed on springback behavior during micro-V-bending. The results indicated that springback tends to increase as the punch radius becomes larger. It was also noted that grain size and punchspeed have a significant effect on minimizing springback [11]. In another investigation, [PERSON] et al. analyzed how variations in temperature, blank holder force, frictional conditions, and forming rate gradients impact springback during warm forming of lightweight alloys. They observed a substantial reduction in springback when the forming temperature exceeded 200 \({}^{\circ}\)C, attributing this to the decreased strength of the material at elevated temperatures. Moreover, higher blank holder forces and increased friction levels contributed to minimizing springback. The study also concluded that reducing the forming rate further helps limit springback [15]. Researchers have employed various experimental methods, such as L-bending, V-bending, and U-bending, to examine and characterize springback, a crucial factor in achieving the desired geometry of bent sheet metal components. Alongside experimental approaches, numerical simulations have become widely adopted to explore the influence of tool geometry and process conditions on springback and to facilitate its prediction [16; 17; 18; 19; 20; 21; 22]. In a study by [PERSON] et al., analytical solutions were proposed to evaluate springback behavior by dividing sheet metal into three segments and applying force using a rigid punch-in combination with an elastic die. The research highlighted the significant role of friction between the die and sheet during deformation. Using an elastic die helped reduce frictional effects, simplifying the shaping process with a rigid punch [23]. [PERSON] et al. performed bending trials using three different types of automotive sheet materials. Their work analyzed variables such as the die gap-to-radius ratio, the coefficient of friction, and applied tensile forces. They also developed graphical models to analyze springback behavior and introduced these findings to the literature [24]. [PERSON] focused on estimating springback through a numerical algorithm that utilized two distinct bending theories.