Mechanical Characterization by Profilometry-Based Indentation Plastometry of Locally Heat-Treated Blanks for Sheet Injection Applications

Abstract:

The sheet injection process, a hybrid sheet-bulk forming technique that integrates bending and injection to create complex features such as ribs, offers significant potential for advanced manufacturing applications. However, its implementation with lightweight aluminium alloys is hindered by their limited room-temperature formability. To address this, locally softened, tailored heat-treated blanks produced via laser heat treatment (LHT) can enhance local ductility while maintaining global strength. This study investigates the mechanical property gradients induced by LHT in 3 mm thick AW6082-T6 aluminium alloy sheets using Profilometry-based Indentation Plastometry (PIP). The laser treatment, performed with a 2.5 kW CO₂ laser, produced localized heat treated regions, whose effectiveness was evaluated through microhardness testing. PIP enabled the direct extraction of local stress-strain curves without the need for specimen extraction and was validated against conventional tensile tests. Results showed that PIP accurately captured local variations in mechanical properties, with heat treated zones exhibiting increased ductility compared to the T6 condition.

• Periodical: Solid State Phenomena (Volume 389)
• Pages: 151-158
• DOI: https://doi.org/10.4028/p-8pDJaR
• Online since: April 2026
• Authors: Angela Cusanno*, João P.G. Magrinho, Antonio Piccininni, Pasquale Guglielmi, Donato Sorgente, Gianfranco Palumbo, Maria Beatriz Silva
• Keywords: Experimentation, Laser Heat Treatment, Profilometry-Based Indentation Plastometry, Sheet-Bulk Forming, Tailored Blanks

References

[1] Li P, Yan Z, Yang Y. Progress in automobile body processing technology: multi-material and lightweight strategies for saving energy and reducing emissions. Journal of the Brazilian Society of Mechanical Sciences and Engineering 2024;46.

DOI: 10.1007/s40430-024-04928-5

[2] Merklein M, Allwood JM, Behrens BA, Brosius A, Hagenah H, Kuzman K, et al. Bulk forming of sheet metal. CIRP Ann Manuf Technol 2012;61:725–45.

DOI: 10.1016/j.cirp.2012.05.007

[3] Magrinho JP, Silva MB, Martins PAF. Injection by sheet-bulk forming. Precis Eng 2019;59:73–80.

DOI: 10.1016/j.precisioneng.2019.06.003

[4] Scharifi E, Yardley VA, Weidig U, Szegda D, Lin J, Steinhoff K. Hot Sheet Metal Forming Strategies for High-Strength Aluminum Alloys: A Review-Fundamentals and Applications. Adv Eng Mater 2023;25.

DOI: 10.1002/adem.202300141

[5] Hirsch J. Recent development in aluminium for automotive applications. Transactions of Nonferrous Metals Society of China (English Edition) 2014;24:1995–2002.

DOI: 10.1016/S1003-6326(14)63305-7

[6] Merklein M, Johannes M, Lechner M, Kuppert A. A review on tailored blanks - Production, applications and evaluation. J Mater Process Technol 2014;214:151–64.

DOI: 10.1016/j.jmatprotec.2013.08.015

[7] Salah ES, Mostafa R, Tawfik MM, Dewidar M. Laser forming technology: a comprehensive review of mechanisms, process optimization, and industrial applications. International Journal of Material Forming 2025;18.

DOI: 10.1007/s12289-025-01943-2

[8] Merklein M, Nguyen H. Advanced laser heat treatment with respect for the application for Tailored Heat Treated Blanks. Phys Procedia, vol. 5, Elsevier B.V.; 2010, p.233–42.

DOI: 10.1016/j.phpro.2010.08.049

[9] Prates PA, Adaixo AS, Oliveira MC, Fernandes J V. Numerical study on the effect of mechanical properties variability in sheet metal forming processes. International Journal of Advanced Manufacturing Technology 2018;96:561–80.

DOI: 10.1007/s00170-018-1604-y

[10] Zhang L, Harrison W, Yar MA, Brown SGR, Lavery NP. The development of miniature tensile specimens with non-standard aspect and slimness ratios for rapid alloy prototyping processes. Journal of Materials Research and Technology 2021;15:1830–43.

DOI: 10.1016/J.JMRT.2021.09.029

[11] Piccininni A, Palumbo G. Numerical modelling of the annealing determined by short-term laser treatment using a physical simulation-based approach. CIRP J Manuf Sci Technol 2023;45:210–24.

DOI: 10.1016/j.cirpj.2023.07.006

[12] Southern TJF, Campbell JE, Fang C, Nemcova A, Bannister A, Clyne TW. Use of hardness, PIP and tensile testing to obtain stress-strain relationships for metals. Mechanics of Materials 2023;187.

DOI: 10.1016/j.mechmat.2023.104846

[13] Sun G, Jiang W, Yang B, Peng W, Shao X, Tu ST. A single-cycle spherical indentation method to determine the tensile properties of materials with different hardening behaviors. Measurement (Lond) 2025;249.

DOI: 10.1016/j.measurement.2025.117026

[14] Clyne TW, Campbell JE, Burley M, Dean J. Profilometry-Based Inverse Finite Element Method Indentation Plastometry. Adv Eng Mater 2021;23.

DOI: 10.1002/adem.202100437

[15] Magrinho JP, Cusanno A, Jesus ML, Piccininni A, Guglielmi P, Palumbo G, et al. Process limits improvement in sheet injection using locally heat-treated aluminium alloy. MATEC Web of Conferences 2025;408:02007.

DOI: 10.1051/matecconf/202540802007

[16] Piccininni A, Palumbo G. Design and optimization of the local laser treatment to improve the formability of age hardenable aluminium alloys. Materials 2020;13.

DOI: 10.3390/ma13071576

[17] Voce E. The relationship between stress and strain for homogeneous deformation. Journal of the Institute Metals 1948:537–62.