Formability and Failure Evaluation of AA3003-H18 Sheets in Single-Point Incremental Forming Process through the Design of Experiments

Abstract

The single-point incremental forming process (SPIF) is one of the emerging manufacturing methods because of its flexibility in producing the desired complex shapes with higher formability at low-cost compared to traditional sheet forming methods. In this research work, we experimentally investigate the forming process to determine the influence of process parameters and their contribution to enhancing the formability without causing a fracture by combining the design of experiments (DOE), grey relational analysis (GRA), and statistical analysis of variance (ANOVA). The surface morphology and the energy dispersive X-ray spectroscopy (EDS) method are used to perform elemental analysis and examine the formed parts during three forming stages. The DOE procedure, a central composite design with a face-centered option, is devised for AA3003-H18 Al alloy sheet for modeling the real-time experiments. The response surface methodology (RSM) approach is adopted to optimize the forming parameters and recognize the optimal test conditions. The statistically developed model is found to have agree with the test measurements. The prediction model’s capability in R2 is computed as 0.8931, indicating that the fitted regression model adequately aligns with the estimated grey relational grade (GRG) data. Other statistical parameters, such as root mean square error (RMSE) and average absolute relative error (AARE), are estimated as 0.0196 and 2.78%, respectively, proving the proposed regression model’s overall closeness to the measured data. In addition, the prediction error range is identified as −0.05 to 0.05, which is significantly lower and the residual data are distributed normally in the design space with variance and mean of 3.3748 and −0.1232, respectively. ANOVA is performed to understand the adequacy of the proposed model and the influence of the input factors on the response variable. The model parameters, including step size, feed rate, interaction effect of tool radius and step size, favorably influence the response variable. The model terms X2 (0.020 and 11.30), X3 (0.018 and 12.16), and X1X2 (0.026 and 9.72) are significant in terms of p-value and F-value, respectively. The microstructural inspection shows that the thinning behavior tends to be higher as forming depth advances to its maximum; the deformation is uniform and homogeneous under the predefined test conditions.

Optimization of Forming Parameters in Incremental Sheet Forming of AA3003-H18 Sheets Using Taguchi Method

“…The material sheet used in this research is the AA3003-H18 aluminum alloy. The sheet material chemical compositions in wt % are as follows: 96.8-99.0% Al, 0.6% Si, 0.7% Fe, 0.05-0.20% Cu, 1.0-1.5% Mn, and 0.10% Zn, and the energy-dispersive X-ray spectroscopy (EDS) analysis conducted employing the field emission scanning electron microscopy method (FESEM-EDS) provides information about the presence of chemical elements present in the material [1]. Further, the test samples were prepared at 0 • , 45 • , and 90 • to the rolling directions to assess the AA3003-H18 Al alloy material properties such as Young's modulus, tensile strength, yield strength, and percentage of total elongation.…”

“…The sheet blank dimension used in the single-point incremental forming process (SPIF) experiment is 280 × 320 mm 2 with a thickness of 0.50 mm. The forming punch tool was fabricated from the high-speed steel (HSS) material, mostly used in cutting tools and metal forming applications, because of its material properties, such as maintaining high hardness at elevated temperatures, wear resistance, and heat resistance [1]. A schematic representation of the SPIF process experimental setup is illustrated in Figure 1; as represented in Figure 1, it has the necessary equipment such as a position sensor, a hemispherical end forming tool, a blank holder, and an external die.…”

“…The manufactured part's surface roughness was estimated as 0.80 µm, 0.66 µm, and 0.64 µm for the lubricants such as engine oil, grease, and oil-grease, respectively. Accordingly, the lubricant mixing oil and grease was identified as the most suitable option from the comparison of surface roughness measurements [1]. Table 2 data were used to perform the real-time SPIF experiments for estimating the surface roughness, as shown in Figure 2a.…”

“…The incremental sheet forming process (ISF) technique, also known as dieless forming, is regarded as one of the flexible manufacturing technologies due to its ability to produce complicated components without using additional dies [1][2][3][4][5]. In detail, the forming process can be performed with the help of a predesigned hemispherical-end forming tool by designing the toolpath, which defines the tool motion based on the desired profiles that need to be manufactured.…”

“…In detail, the forming process can be performed with the help of a predesigned hemispherical-end forming tool by designing the toolpath, which defines the tool motion based on the desired profiles that need to be manufactured. Due to aforementioned advantages, this process is widely adopted in industrial applications such as medical, automotive, aerospace, and civil sectors [1][2][3][4][5]. However, although this process has noticeable advantages, it also tends to have drawbacks [6][7][8][9][10], including the material formability [11] issues such as achieving proper height and wall angle, controlling thinning behavior, reducing forming force [12][13][14], and the pillow effect.…”