Experimental Investigation of the Thickness Distribution in a Three-Layer Aluminum-Polyethylene Sheet During Two-Point Incremental Forming Using Central Composite Design

Document Type : Research Paper

Authors

Faculty of Mechanical Engineering, University of Kashan, Kashan, Iran

Abstract

The two-point incremental forming (TPIF) process is an advanced and flexible method for manufacturing complex metal parts without the need for dedicated molds. In this study, the thickness distribution of three-layer aluminum–polyethylene (Al–PE–Al) sheets formed using TPIF was experimentally investigated. The sheets, measuring 180 × 180 mm and consisting of 1 mm aluminum 1050 layers and a 1 mm HDPE core, were formed into truncated pyramid geometries on a CNC machine. Using a central composite design methodology, input parameters including tool rotation speed, feed rate, and vertical step depth were varied, with thickness distribution measured as the output parameter. After forming, samples were cut using waterjet cutting to prevent thermal damage to the polymer layer. Thickness at various points along a central path was precisely measured using a vision measuring machine (VMM). Results showed that the top aluminum layer experienced greater thickness reduction than the bottom layer (23.30–39.75% vs. 12.71–32.75%) due to direct tool contact and higher local stresses. The bottom layer, protected by the polymer core, exhibited less thinning. Overall, the three-layer sheet (26.05–44.83%) showed greater thickness reduction than either aluminum layer individually, reflecting strain redistribution through the viscoelastic HDPE core and interaction between the polymer and aluminum layers. These findings emphasize non-uniform stress distribution and the importance of process parameter optimization for controlling layer-specific deformation and overall thickness uniformity.

Keywords


[1] Trzepieciński, T., Najm, S. M., Pepelnjak, T., Bensaid, K., & Szpunar, M. (2021). New advances and future possibilities in forming technology of hybrid metal–polymer composites used in aerospace applications. Journal of Composites Science, 5(8), 217. https://doi.org/10.3390/jcs5080217
[2] Marques, A. E., Prates, P. A., Pereira, A. F. G., Sakharova, N. A., Oliveira, M. C., & Fernandes, J. V. (2020). Numerical study on the forming behaviour of multilayer sheets. Metals, 10(6), 716. https://doi.org/10.3390/met10060716
[3] Maqbool, F., Maaß, F., Bühl, J., Hahn, M., Hajavifard, R., Walther, F., & Tekkaya, A. E. (2021). Targeted residual stress generation in single and two point incremental sheet forming (ISF). Archive of Applied Mechanics, 91, 3465–3487. https://doi.org/10.1007/s00419-021-01935-z
[4] Murugesan, M., Yu, J. H., Jung, K. S., Cho, S. M., Bhandari, K. S., & Lee, C. W. (2022). Optimization of forming parameters in incremental sheet forming of AA3003-H18 sheets using Taguchi method. Materials15(4), 1458. https://doi.org/10.3390/ma15041458
[5] Gao, K., Zhang, X., Liu, B., He, J., Feng, J., Ji, P., Fang, W., & Yin, F. (2020). The deformation characteristics, fracture behavior and strengthening toughening mechanisms of laminated metal composites: A review. Metals, 10(1), 4. https://doi.org/10.3390/met10010004
[6] T Majagi, S. D., Chandramohan, G., & Senthil Kumar, M. (2015). Effect of incremental forming process parameters on aluminum alloy using experimental studies. Advanced Materials Research, 1119, 633–639. https://doi.org/10.4028/www.scientific.net/amr.1119.633
[7] Popp, G. P., Racz, S. G., Breaz, R. E., Oleksik, V. Ș., Popp, M. O., Morar, D. E., Chicea, A. L., & Popp, I. O. (2024). State of the art in incremental forming: Process variants, tooling, industrial applications for complex part manufacturing and sustainability of the process. Materials, 17(23), 5811. https://doi.org/10.3390/ma17235811
[8] Szpunar, M., Ostrowski, R., Trzepieciński, T., & Kaščák, Ľ. (2021). Central composite design optimisation in single point incremental forming of truncated cones from commercially pure titanium grade 2 sheet metals. Materials14(13), 3634. https://doi.org/10.3390/ma14133634
[9] Ghasemi, H., & Soltani, B. (2014). Experimental investigation on the effective parameters on forming force, dimensional accuracy and thickness distribution in single point incremental forming. Modares Mechanical Engineering, 14(1), 89–96. 2 https://dor.isc.ac/dor/20.1001.1.10275940.1393.14.1.17.6
[10] Honarpisheh, M., Ebrahimi, M. R., & Mansouri, H. (2019). Investigation of springback angle in single point incremental forming process on explosive welded Cu/St/Cu multilayer. Journal of Modern Processes in Manufacturing and Production, 8(3), 13–26. https://journals.iau.ir/article_664286.html
[11] Rezaei, H., & Honarpisheh, M. (2022). Experimental and numerical investigation of forming limit diagram of CP‑Ti/St12 bimetal in incremental forming process. Strength of Materials, 54(4), 681–694. https://doi.org/10.1007/s11223-022-00446-8
[12] Deilami Azodi, H., Rezaei, S., Beygi, A. Z., & Badparva, H. (2022). Investigation of parameters influencing forming force and thickness distribution in single point incremental forming of AA3105‑St12 two‑layer sheet. Iranian Journal of Materials Forming, 9(2), 46–57.  https://doi.org/10.22099/ijmf.2022.42993.1215
[13] Deilami Azodi, H., Rezaee, S., Badparva, B., & Zeinolabedin Beygi, A. (2022). Optimizing AA3105‑St12 two‑layer sheet in incremental sheet forming process using neural network and multi‑objective genetic algorithm. Modares Mechanical Engineering, 22(2), 121–132. SID. https://dor.isc.ac/dor/20.1001.1.10275940.1400.22.2.4.7
[14] Esmailian, M., Honarpisheh, M., & Gheysarian, A. (2023). Investigation of fracture depth of metal‑polymer three layer sheet in single‑point incremental forming process. Iranian Journal of Materials Forming, 10(1), 39–52. https://doi.org/10.22099/ijmf.2023.46874.1249
[15] Tayebi, P., & Hashemi, R. (2024). Study of single point incremental forming limits of Al1050/Mg‑AZ31B two‑layer sheets fabricated by roll bonding technique: Finite element simulation and experiment. Journal of Materials Research and Technology, 29, 149–169. https://doi.org/10.1016/j.jmrt.2024.01.085
[16] Tayebi, P., Nasirin, A. R., Akbari, H., & Hashemi, R. (2024). Experimental and numerical investigation of forming limit diagrams during single‑point incremental forming for Al/Cu bimetallic sheets. Metals, 14(2), 214. https://doi.org/10.3390/met14020214
[17] Li, X., Pan, J., Liu, L., Huang, Z., & Wang, Q. (2016). Effect of some process parameters on geometric errors in two point incremental forming for Al‑Cu‑Mg aluminum alloy. Journal of Physics: Conference Series, 734, 032078. https://doi.org/10.1088/1742-6596/734/3/032078
[18] Ou, L., An, Z., Gao, Z., Zhou, S., & Men, Z. (2020). Effects of Process Parameters on the Thickness Uniformity in two-point incremental forming (TPIF) with a positive die for an irregular stepped part. Materials13(11), 2634. https://doi.org/10.3390/ma13112634
[19] Visagan, A., & Ganesh, P. (2022). Parametric optimization of two‑point incremental forming using GRA and TOPSIS. International Journal of Simulation Modelling, 21(4), 615–626. https://doi.org/10.2507/IJSIMM21-4-622
[20] Singal, A. H., Farhood, N. H., Al‑Qassar, A. A. (2023). Experimental inspection of residual stresses induced in parts produced by two‑point incremental forming (TPIF) process. Journal of Engineering Science and Technology, 18(1), 347–356. https://doi.org/10.3390/jeset1841
[21] Thokale, M., Gupta, R., & Sharma, V. (2024). Enhancing sheet metal forming through ultrasonic‑assisted incremental techniques: A comparative analysis of SPIF and TPIF. SGVU International Journal of Convergence of Technology and Management, 10(2), 51–58.
[22] Harhash, M., & Palkowski, H. (2021). Incremental sheet forming of steel/polymer/steel sandwich composites. Journal of Materials Research and Technology, 13, 417–430. https://doi.org/10.1016/j.jmrt.2021.04.088
[23] Trzepieciński, T., Najm, S. M., Pepelnjak, T., Bensaid, K., & Szpunar, M. (2022). Incremental sheet forming of metal-based composites used in aviation and automotive applications. Journal of Composites Science6(10), 295. https://doi.org/10.3390/jcs6100295
[24] Zhao, X., & Ou, H. (2023). A new flexible multi‑point incremental sheet forming process with multi‑layer sheets. Journal of Materials Processing Technology, 322, 118214. https://doi.org/10.1016/j.jmatprotec.2023.118214
[25] Zhao, X., & Ou, H. (2024). A new hybrid stretch forming and double‑layer two‑point incremental sheet forming process. Journal of Materials Research and Technology, 30, 3485–3509. https://doi.org/10.1016/j.jmrt.2024.04.093
[26] Önal, Ü., Seçgin, Ö., Özsert, İ. et al. (2024). A new approach to multi‑stage incremental forming method. Arabian Journal for Science and Engineering, 49, 15325–15334. https://doi.org/10.1007/s13369-024-08970-2
[27] Maaß, F., Hahn, M., & Tekkaya, A. E. (2021). Adjusting residual stresses by flexible stress superposition in incremental sheet metal forming. Archive of Applied Mechanics, 91, 3489–3499. https://doi.org/10.1007/s00419-021-01929-x
[28] Cen, H. T., Chi, L. X., & Li, H. (2009). An experimental study on composites machining using abrasive water jet technology. Key Engineering Materials, 407–408, 582–585. https://doi.org/10.4028/www.scientific.net/KEM.407-408.582