Multi-Response Optimization of Mechanical Properties and Quantitative Porosity of A356 Aluminum Alloy Subjected to T6 Heat Treatment Using Response Surface Methodology
Optimasi Multi-Respons Sifat Mekanik dan Porositas Kuantitatif Paduan Aluminium A356 pada Perlakuan Panas T6 Menggunakan Response Surface Methodology
DOI:
https://doi.org/10.21070/r.e.m.v11i2.1871Keywords:
A356, aluminum alloy, Response Surface Methodology, T6 heat treatment, quantitative porosityAbstract
This study addresses key methodological gaps in prior T6 heat-treatment research on A356 aluminum alloy, namely the ambiguity of treatment-temperature definitions, reliance on perceived (non-quantitative) porosity assessment, incomplete statistical testing across mechanical responses, and the use of single-factor discrete temperature screening instead of a continuous optimization design. A two-factor Central Composite Design (aging temperature 162-183 °C; aging time 2.3-13.7 h) following a fixed solution treatment (540 °C/6 h, water quench) was employed, comprising 13 experimental runs. Responses (tensile strength, hardness, elongation, and quantitative porosity via image analysis and Archimedes density) were modeled using Response Surface Methodology (RSM) and optimized jointly through a composite desirability function. Quadratic regression models were statistically significant (p < 0.001) for all responses. The optimum condition was identified at an aging temperature of 173.2 °C for 7.8 h, yielding a predicted tensile strength of 283.1 MPa, hardness of 93.2 HB, elongation of 10.0%, and porosity as low as 3.1%, confirmed experimentally within 4% deviation. Secondary Dendrite Arm Spacing (SDAS) was quantitatively correlated with both tensile strength and hardness (R² > 0.85). The findings extend existing T6 optimization literature by providing a validated, continuous, multi-response optimization framework with quantitative defect characterization for A356 components.
References
[1] H. Azimi, S. Nourouzi, and R. Jamaati, “Effects of Ti particles and T6 heat treatment on the microstructure and mechanical properties of A356 alloy fabricated by compocasting,” Mater. Sci. Eng. A, vol. 818, no. May, p. 141443, 2021, doi: 10.1016/j.msea.2021.141443.
[2] Z. Wei, Y. Lei, H. Yan, X. Xu, and J. He, “Microstructure and mechanical properties of A356 alloy with Y addition processed by hot extrusion,” J. Rare Earths, 2018, doi: 10.1016/j.jre.2018.11.008.
[3] J. Wen-ming, F. A. N. Zi-tian, and L. I. U. De-jun, “Microstructure , tensile properties and fractography of A356 alloy under as-cast and T6 obtained with expendable pattern shell casting process,” Trans. Nonferrous Met. Soc. China, vol. 22, pp. s7–s13, 2012, doi: 10.1016/S1003-6326(12)61676-8.
[4] T. Kimura and T. Nakamoto, “Microstructures and mechanical properties of A356 (AlSi7Mg0.3) aluminum alloy fabricated by selective laser melting,” JMADE, vol. 356, 2015, doi: 10.1016/j.matdes.2015.10.065.
[5] W. Xiong et al., “A novel semi-solid rheo-squeeze strategy for optimizing the microstructure and mechanical properties of A356 aluminum alloy,” J. Sci. Adv. Mater. Devices, vol. 10, no. 4, p. 101050, 2025, doi: 10.1016/j.jsamd.2025.101050.
[6] P. Ye, F. Jiang, F. Wu, K. Ye, and Y. Fan, “Effects of Zr and Y additions on microstructure and mechanical properties of cast A356 alloy,” J. Mater. Res. Technol., vol. 30, no. April, pp. 6355–6365, 2024, doi: 10.1016/j.jmrt.2024.05.058.
[7] D. Teng, G. Zhang, S. Zhang, and J. Li, “Response of mechanical properties of A356 alloy to continuous rheological extrusion Al-5Ti-0 . 6C-xCe alloy addition upon different Ce contents,” J. Mater. Res. Technol., vol. 27, pp. 209–224, 2023, doi: 10.1016/j.jmrt.2023.09.203.
[8] G. Gu, L. Xiang, R. Li, and H. Zheng, “Microstructure , segregation and mechanical properties of A356 alloy components fabricated by rheo-HPDC combined with the swirled enthalpy equilibration device ( SEED ) process,” J. Mater. Res. Technol. Technol., 2023, doi: 10.1016/j.jmrt.2023.09.153.
[9] J. Klemenc and S. G. Steinacher, Matej Steinacher, “Microstructure, mechanical properties and fatigue behaviour of a new high-strength aluminium alloy AA 6086,” J. Alloy. Compd., vol. 941, pp. 1–13, 2023, doi: 10.1016/j.jallcom.2023.168976.
[10] S. Ma, X. Zhang, T. Chen, and X. Wang, “Microstructure-based numerical simulation of the mechanical properties and fracture of a Ti-Al 3 Ti core-shell structured particulate reinforced A356 composite,” Mater. Des., vol. 191, p. 108685, 2020, doi: 10.1016/j.matdes.2020.108685.
[11] V. A. Adebiyi and O. B. Malachi, “Microstructural evaluation of aluminium alloy A365 T6 in machining operation,” Integr. Med. Res., vol. 8, no. 3, pp. 3213–3222, 2019, doi: 10.1016/j.jmrt.2019.05.009.
[12] V. S. Aigbodion and I. C. Ezema, “Multifunctional A356 alloy / PKSAnp composites : Microstructure and mechanical properties,” Def. Technol., vol. 16, no. 3, pp. 731–736, 2020, doi: 10.1016/j.dt.2019.05.017.
[13] K. T. Akhil and R. Sellamuthu, “The Effect of Heat Treatment and Aging Process on Microstructure and Mechanical Properties of A356 Aluminium Alloy Sections in Casting,” Procedia Eng., vol. 97, pp. 1676–1682, 2014, doi: 10.1016/j.proeng.2014.12.318.
[14] R. S. K.T. Akhil, Sanjivi Arul, “The Effect of Section Size on Cooling Rate, Microstructure and Mechanical Properties of A356 Aluminium Alloy in Casting,” Procedia Mater. Sci., vol. 5, pp. 362–368, 2014, doi: 10.1016/j.mspro.2014.07.278.
[15] D. Ö. Ijlal Simsek, “Investigation of the effects of Mg amount on microstructure and wear behavior of Al-Si-Mg alloys,” Eng. Sci. Technol. , an Int. J., vol. 22, pp. 370–375, 2019, doi: 10.1016/j.jestch.2018.08.016.
[16] A. P. Silva, T. S. Costa, and O. L. Rocha, “Investigation on microstructural and microhardness evolution in as-cast and T6 / heat-treated samples of a horizontally solidified AlSiCu alloy,” Integr. Med. Res., vol. 8, no. 5, pp. 5046–5052, 2019, doi: 10.1016/j.jmrt.2019.06.054.
[17] T. Tiwari and and J. B. P. Gan, Tat-hean, “Data-Driven Optimization of Size-Aware T6 Heat Treatment Parameters for A356 Aluminum Alloy,” Metals (Basel)., vol. 356, pp. 1–29, 2026, doi: https://www.mdpi.com/2075-4701/16/6/615.
[18] K. C. Nnakwo et al., “Tailoring the tensile characteristics , hardness and impact strength of A356 hypoeutectic alloy via multi-step aging heat treatment,” Discov. Mater., 2025, doi: https://doi.org/10.1007/s43939-025-00412-6.
[19] M. H. Abdelaziz and V. S. and F. H. S. , Agnes M. Samuel, Herbert W. Doty, “Mechanical Performance and Precipitation Behavior in Al-Si-Cu-Mg Cast Alloys : Effect of Prolonged Thermal Exposure,” Materials (Basel)., 2022, doi: https://doi.org/10.3390/ma15082830.
[20] E. G. C. Rodas et al., “Analysis of Porosity in Aluminum Alloy ( AlSi10Mg ) Using Tomographic Image Processing,” J. manufakturing Mater. Process., pp. 1–17, 2025, doi: https://doi.org/10.3390/jmmp9110374.
[21] X. ping Hu, Y. Zhao, Q. Wang, X. zhi Zhang, R. xin Li, and B. rong Zhang, “Effect of pouring and cooling temperatures on microstructures and mechanical properties of as-cast and T6 treated A356 alloy,” China Foundry, vol. 16, no. 6, pp. 380–385, 2019, doi: 10.1007/s41230-019-9068-8.
[22] J. Wang, X. Chen, L. Yang, and G. Zhang, “Effect of preheat & post-weld heat treatment on the microstructure and mechanical properties of 6061-T6 aluminum alloy welded sheets,” Mater. Sci. Eng. A, vol. 841, p. 143081, 2022, doi: https://doi.org/10.1016/j.msea.2022.143081.
[23] M. J. Roy and D. M. Maijer, “Response of A356 to warm rotary forming and subsequent T6 heat treatment,” Mater. Sci. Eng. A, 2014, doi: 10.1016/j.msea.2014.05.088.
[24] S. C. Ram, K. Chattopadhyay, and I. Chakrabarty, “Microstructures and high temperature mechanical properties of A356-Mg2Si functionally graded composites in as-cast and artificially aged (T6) conditions,” J. Alloys Compd., 2019, doi: 10.1016/j.jallcom.2019.07.075.
Published
License
Copyright (c) 2026 Joni Arif, syaiful arif, Widarto, Ardian Maulana
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright Notice
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution 4.0 International License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
