INFLUENCE OF HEAT TREATMENT AND NANOPARTICLES ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ALUMINUM ALLOY

The microstructure and mechanical properties of a matrix composite based on aluminum alloy AA2024 reinforced with TiO₂ nanoparticles have been studied. AlMgCu intermetallic compound is formed in an aluminum matrix reinforced with TiO₂ nanoparticles with various concentrations (0, 2.5, 5.0 and 7.5 %) obtained using mixing casting technology. The mixing casting process was followed by subsequent heat treatment at 500 °C. The alloy was then rapidly cooled in water to a temperature of 25 °C and aged at 185 °C for 3 hours. This treatment leads to the dissolution of titanium nanoparticles in the matrix, and ultrafine compounds are formed around the grains of the aluminum composite. According to the results obtained, the compounds Al₇Cu₂Fe and Al(Cu, Mn, Fe, Si) form a single structure in the interendritic regions. When adding up to 2.5 % titanium oxide, the number of fine needle–like Al – Cu – Mg secretions near the dendritic regions increased, but further addition of titanium oxide reduced their number in this zone. After heat treatment with the addition of up to 7.5 % titanium oxide, needle–like Al – Cu – Mg secretions in the dendritic regions disappeared and fell out in the inner zone of the dendrites. When TiO₂ was added and heat treatment was carried out, the unreacted intermetallides and Al₃Ti were completely converted into Al₃MgCu. With an increase in the TiO₂ content from 5.0 to 7.5 %, instead of Al₂CuMg secretions, Al₆Mg₄Cu secretions were formed in the aluminum matrix. The addition of 5 % titanium oxide increases the hardness of the composite by about 33 % compared to samples without titanium oxide nanoparticles

1. Gnanavelbabu A., Surendran K.T.S., Kumar S. Process optimization and studies on mechanical characteristics of AA2014/Al2O3 nanocomposites fabricated through ultrasonication assisted stir–squeeze casting. International Journal of Metal casting. 2022;16(2):759–782. https://doi.org/10.1007/s40962-021-00634-3

2. ‏Liu F., Zhu X., Ji S. Effects of Ni on the mi-crostructure, hot tear and mechanical properties of Al–Zn–Mg–Cu alloys under as-cast condition. Journal of Alloys and Compounds. 2020; 821:153458. https://doi.org/10.1016/j .jallcom.2019.153458

3. Aynalem G.F. Processing methods and me-chanical properties of aluminum matrix composites. Advances in Materials Science and Engineering. 2020;2020:1–19.‏ https://doi.org/ 10.1155/2020/3765791

4. Ramesh R., Roseline V.A., Gowrishankar. Production and characterization of aluminum metal matrix composite rein-forced with Al3Ni by stir and squeeze casting. Applied Mechanics and Materials. 2015;766–767:315–319. http://dx.doi.org/10.4028/www.scientific.net/AMM.766-767.315

5. Op A.R.N., Arul S. Effect of nickel reinforcement on micro hardness and wear resistance of aluminum alloy Al7075. Materials Today: Proceedings. 2020; 24:1042–1051.‏ https://doi.org/10.1016/j.matpr.2020.04.418

6. Krishna M.G., Kumar K.P., Swapna M.N., Rao J.B., Bhargava N.R.M.R. Fabrication, characterization and mechanical behavior of A356/copper particulate reinforced metallic composites. Materials Today: Proceedings. 2018;5(2):7685–7691. https://doi.org/10.1016/j.matpr.2017.11.444

7. Mondal D.P., Jha N., Badkul A., Das S., Yadav M.S., Jain P. Effect of calcium addition on the microstructure and compressive deformation behavior of 7178 aluminum alloy. Materials & Design. 2011;32(5):2803–2812. https://doi. org/10.1016/j.matdes.2010.12.056

8. Hekmat-Ardakan A., Ajersch F. Effect of isothermal ageing on the semi-solid microstructure of reprocessed and partially remelted of A390 alloy with 10% Mg addition. Materials characterization. 2010;61(8):778–785.‏ https://doi.org/10.1016/j.matchar.2010.04.012

9. Mahan H.M., Konovalov S.V., Panchenko I.A., Pashkova D.D. Investigation of the properties and structure of aluminum matrix composites reinforced with TiO2 particles. Polzunovsky bulletin. 2022;4–2:7–13.‏ (In Russ.). https://doi.org/10.25712/ASTU.2072-8921.2022.4.2.001

10. Deevi S.C., Sikka V.K. Nickel and iron alu-minides: an overview on properties, pro-cessing, and applications. Intermetallic. 1996;4(5):357–375. https://doi.org/10.1016/ 0966-9795(95)00056-9

11. Vishwanatha A.D., Panda B., Shivanna D.M. Effect of a T6 aging treatment on the corrosion behavior of in-situ AlxNiy reinforced AA6061 composite. Materials Today: Proceedings. 2021;44(6):4112–4117. https://doi.org/10. 1016/j.matpr.2020.10.455

12. Xiao L., Yu H., Qin Y., Liu G., Peng Z., Tu X., Zhao X. The evolution of microstructure and mechanical properties at elevated temperature of cast Al–Li–Cu–Mg alloys with Ni addition. Journal of Materials Research and Technology. 2020; 9:11069–11079. https://doi.org/ 10.1016/j.jmrt.2020.07.098

13. Han J.Q., Wang J.S., Zang M.-S., Niu K.M. Relationship between amounts of low-melting-point eutectics and hot tearing susceptibility of ternary Al− Cu− Mg alloys during solidification. Transactions of Nonferrous Metals Society of China. 2020;30(9):2311–2325. https://doi.org/10.1016/S1003-6326(20)65381-X

14. Mahan H.M., Konovalov S.V., Osintsev K., Panchenko I. The influence of TiO2 nanoparticles on the mechanical properties and microstructure of AA2024 aluminum alloy. Materials and Technology. 2023;57(4):379–384. https://doi.org/10.17222/mit.2023.898

15. Gxowa-Penxa Z., Daswa P., Modiba R., Mathabathe M.N., Bolokang A.S. De-velopment and characterization of Al–Al3Ni–Sn metal matrix composite. Materials Chemistry and Physics. 2021; 259:124027. https://doi.org/10.1016/ j.matchemphys.2020.124027

16. Mahan H.M., Konovalov S.V., Panchenko I. Effect of heat treatment on the mechanical properties of the aluminium alloys AA2024 with nanoparticles. International Journal of Applied Science and Engineering. 2023;20(2):2022324. https://doi.org/10.6703/IJASE.202306_20(2).011

17. Mohamed A.M.A., Samuel F.H., Al kahtani S. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys. Materials Science and Engineering: A. 2013;577: 64–72. https://doi.org/10.1016/j.msea.2013.03.084

18. Mahan H.M., Konovalov S.V., Panchenko I., Al-Obaidi M.A. The effects of titanium dioxide (TiO2) content on the dry sliding behaviour of AA2024 aluminium composite. Journal of Mechanical Engineering. 2023;20(3):1823–5514. https://doi.org/10.24191/jmeche. v20i3.23910

19. Wang, Y., Lu, Y., Zhang, S., Zhang, H., Wang, H., Chen, Z. Characterization and strengthening effects of different precip-itates in Al-7Si-Mg alloy Journal of Alloys and Compounds. 2021; 885: 161028. https://doi.org/10. 1016/j.jallcom.2021.161028

20. Taylor R.P., McClain S.T., Berry J.T. Uncer-tainty analysis of metal-casting porosty measurements using Archimedes’ principle. International Journal of Cast Metals Research. 1999;11(4):247–257. https://doi.org/10. 1080/13640461.1999.11819281

21. Farajollahi R., Aval H.J., Jamaati R. Effects of Ni on the microstructure, mechanical and tribological properties of AA2024-Al3NiCu composite fabricated by stir casting process. Journal of Alloys and Compounds. 2021; 887:161433.‏ https://doi.org/10.1016/j.jallcom.2021.161433

22. Mahan H.M., Konovalov S.V., Najm S.M., Mihaela O., Trzepieciński T. Experimental and numerical investigations of the fatigue life of AA2024 aluminum alloy-based nanocomposite reinforced by TiO2 nanoparticles under the effect of heat treat-ment. International Journal of Precision Engineering and Manufacturing. 2023:1–13.‏https://doi.org/10.1007/s12541-023-00906-4