Effects of quenching temperature on the structure, segregation, and properties of the AM4.5Kd + 0.2 wt.% La alloy after artificial aging

The identification of structural components in the AM4.5Kd + 0.2 wt.% La alloy, subjected to quenching at different temperatures (535–605 °C) and artificial aging at 155 °C for 4 h, was conducted through electron microscopy and XRD. An increase in the quenching temperature from 535 to 605 °C promotes the enlargement of structural components, including the α-solid solution, various aluminides, and eutectics. We observed that the base metal is not homogeneous in its chemical composition, consisting of two types of solid solutions: α₁ and α₂. The Cu and Mn solubility in the α₂-solid solution is higher than in the α₁-solid solution. As the quenching temperature increases to t_q = 605 °C, the copper content in the α₁-solid solution decreases. In contrast, the copper content in the α₂-solid solution follows a curve with two maxima at 545 °С (4.5 at.%) and 585 °С (8.7 at.%). The Mn content in the α₁-solid solution decreases sharply to the 545 °С quenching temperature and remains relatively constant up to t_q = 605 °С (0.2 at.%). The Mn content in the α₂-solid solution follows a curve with its maximum at t_q = 545 °С (4.3 at.% Mn). Subsequent temperature rise results in a sharp drop in Mn content from 1.0 at.% at t = 565 °С to 0.3 at.% at 605 °С. Hence, the max solubility of Cu and Mn in the α2-solid solution occurs at 545 °C. At 585 °С, only an elevated Cu content (~8.7 at.%) was observed. Aluminides of alloying elements with different stoichiometries crystallize at different quenching temperatures, with complex Al_xTi_yLa_zCu_vCd_w and Al_xCu_yMn_zCd_v alloyed aluminides being most commonly found. ncreasing the quenching temperature to 535–545 °С results in higher hardness of the AM4.5Kd + 0.2 wt.% of La alloy, reaching 98–104 HB, with subsequent decrease to 60 HB as the quenching temperature reaches 605 °С. The hardness of the unhardened alloy is 60 HB. The optimal quenching temperature for the AM4.5Kd + 0.2 wt.% of La alloy is in the range of 535–545 °С. This temperature corresponds to the highest hardness of the alloy and the microhardness of the aluminide.

1. Ogorodov D.V., Trapeznikov A.V., Popov D.A., Pentyukhin S.I. Development of foundry aluminum alloys in VIAM (to the 120th anniversary of the birth of I.F. Kolobnev). Trudy VIAM. 2017;2(50):105—122. (In Russ.).

2. Belov N.A., Alabin A.N. Promising aluminum alloys with increased heat resistance for reinforcement engineering as a possible alternative to steels and cast iron. Armaturostroenie. 2010;2(65):50—54. (In Russ.).

3. Квасова Ф.И., Фридляндер И.Н. Промышленные алюминиевые сплавы. М.: Металлургия, 1984. 528 c.

4. Алиева С.Г., Альтман М.Б., Амбарцумян С.М. Промышленные алюминиевые сплавы. М.: Металлургия, 1984. 527 c.

5. Patel N., Joshi M., Singh A., Pradhan A.K. Effect of solution heat treatment on microstructure and some properties of Al—Cu—Mg alloy. Transactions of the Indian Institute of Metals. 2023;76(10):2681—2689. https://doi.org/10.1007/s12666-023-02961-x

6. Aryshensky E.V., Aryshensky V.Yu., Drits А.М., Grechnikov F.V., Ragazin А.А. Thermal treatment effect on the mechanical properties of 1570, 1580 and 1590 aluminum alloys. Vestnik of Samara University. Aerospace and Mechanical Engineering. 2022;21(4):76—87. (In Russ.). https://doi.org/10.18287/2541-7533-2022-21-4-76-87

7. Korotkova N.O., Belov N.A., Timofeev V.N., Motkov M.M., Cherkasov S.O. Influence of heat treatment on the structure and properties of an Al—7% REM conductive aluminum alloy casted in an electromagnetic crystallizer. Physics of Metals and Metallography. 2020;121(2): 173—179. https://doi.org/10.31857/S0015323020020096

8. Paitova O.V., Bobruk E.V., Skotnikova M.A. Optimization of the structure and properties of the Al—Cu—Mg system aluminum alloy. Journal of Instrument Engineering. 2020;63(5):476—482. (In Russ.). https://doi.org/10.17586/0021-3454-2020-63-5-476-482

9. Zenin M.N., Guryev A.M., Ivanov S.G., Guryev M.A., Chernykh E.V. Influence of high-temperature annealing of aluminum alloys AMg6 and V95 on their structural-phase state and strength proper-ties. Fundamental’nye Problemy Sovremennogo Materialovedenia (Basic Problems of Material Science (BPMS)). 2022;19(1):106—114. (In Russ.). https://doi.org/10.25712/ASTU.1811-1416.2022.01.012

10. Zhou W.B., Teng G.B., Liu C.Y., Qi H.Q., Huang H.F., Chen Y., Jiang H.J. Microstructures and mechanical properties of binary Al—Zn alloys fabricated by casting and heat treatment. Journal of Materials Engineering and Performance. 2017;26:3977—3982. https://doi.org/10.1007/s11665-017-2852-y

11. Tan E. Change in the wear characteristics of T6 heattreated 2024, 6063, and 7075 alloys at different quenching temperatures. Journal of Materials Engineering and Performance. 2023;32:1—13. https://doi.org/10.1007/s11665-023-08177-w

12. Anjabin N. Modeling the age-hardening process of aluminum alloys containing the prolate/oblate shape precipitates. Metals and Materials International. 2021;27:1620—1630. https://doi.org/10.1007/s12540-019-00579-7

13. Alexandrov А.А., Butorin D.V., Daneev R.A., Livshits A.V. Error estimation of the heat transfer coefficient determination devices based on mathematical modeling. Vestnik RGUPS. 2019;(4):8—16. (In Russ.).

14. Krivopalov I.V., Baturin A.P., Erisov Ya.A. Application of computer simulation to determine the influence of quenching parameters on the geometry of parts from AK6 aluminium alloy. Izvestiya Samarskogo Nauchnogo Tsentra Rossiiskoi Akademii Nauk. 2021:23(6):5—9. (In Russ.). https://doi.org/10.37313/1990-5378-2021-23-6-5-9

15. Hu Y., Wang G., Ye M., Wang S., Wang L., Rong Y. A precipitation hardening model for Al—Cu—Cd alloys. Materials & Design. 2018;151:123—132. https://doi.org/10.1016/j.matdes.2018.04.057

16. Hu Y., Wang G., Ji Y., Wang L., Rong Y., Chen L.Q. Study of θ’precipitation behavior in Al—Cu—Cd alloys by phase-field modeling. Materials Science and Engineering: A. 2019;746:105—114. https://doi.org/10.1016/j.msea.2019.01.012

17. Liu X., Wang G., Hu Y., Ji Y., Rong Y., Hu Y., Chen L.Q. Multi-scale simulation of Al—Cu—Cd alloy for yield strength prediction of large components in quenchingaging process. Materials Science and Engineering: A. 2021;814:141223. https://doi.org/10.1016/j.msea.2021.141223

18. Choudhary C., Bar H.N., Arif S. Sahoo K.L., Mandal D. Effect of structural refinement and modification on the mechanical properties of Al—7Si alloy. Journal of Materials Engineering and Performance. 2023;1—13. https://doi.org/10.1007/s11665-023-08313-6

19. Ruan Q., Meng C., Xie Z., Tao Z., Wu J., Peng Y., Tang H., Chen P. Effect of (Ti + V)B2 on the grain structure of Al—7Si alloy. Transactions of the Indian Institute of Metals. 2023;76(10):2765—2771. https://doi.org/10.1007/s12666-023-02954-w

20. Sahin H., Dispinar D. Effect of rare earth elements erbium and europium addition on microstructure and mechanical properties of A356 (Al—7Si—0.3Mg) alloy. International Journal of Metalcasting. 2023;17(4):2612—2621. https://doi.org/10.1007/s40962-023-01060-3

21. Лапоногова П.А., Колисова М.В., Гончаров А.В., Дзюба Г.С. Применение скандия для модифицирования алюминиевых сплавов на примере ВАЛ10. В сб.: Инновационные технологии в литейном производстве. М.: ИИУ МГОУ, 2019. С. 75—78.

22. Amer S.M., Barkov R.Y., Prosviryakov A.S., Pozdniakov A.V. Structure and properties of new heat-resistant cast alloys based on the Al—Cu—Y and Al—Cu—Er systems. Physics of Metals and Metallography. 2021;122(9):908-914. https://doi.org/10.31857/S0015323021090023

23. Bazhenov V.E., Baranov I.I., Titov A.Yu., Sannikov A.V., Ozherelkov D.Yu., Lyskovich A.A., Koltygin A.V., Belov V.D. Influence of Ti, Sr and B additions on the fluidity of A356.2 aluminium alloy. Izvestiya. Non-Ferrous Metallurgy. 2022;28(4):55—66. (In Russ.). https://doi.org/10.17073/0022-3438-2021-4-55-66

24. Abramov A.A. Aluminium-titanium-boron alloying composition as an effective grain modifier for cast aluminum alloys. Metallurgiya Mashinostroeniya. 2021;(2):2—4. (In Russ.).

25. Andrushevich A.A., Sadokha M.A. Shrinkage phenomena in silumins when treated with long-acting modifiers. Litiyo i Metallurgiya (Foundry Production and Metallurgy). 2022;(3):30—35. (In Russ.). https://doi.org/10.21122/1683-6065-2022-3-30-35

26. Shlyaptseva A.D., Petrov I.A., Ryakhovsky A.P. Complex modification of industrial silumins. Teoriya i Tekhnologiya Metallurgicheskogo Proizvodstva. 2021;1(36):4—10. (In Russ.).

27. Ри Х., Ри Э.Х., Зернова Т.С., Калаушин М.А., Ри В.Э., Ермаков М.А. Модификатор: Пат. 2521915 (РФ). 2012.

28. Добаткин В.А., Елагин В.И., Федоров В.М. Быстрозакристаллизующиеся алюминиевые сплавы. М.: ВИЛС, 1995. 341 с.

29. Xiao-hui Ao, Shu-ming Xing, Bai-shui Yu, Qing-you Han. Effect of Ce addition on microstructures and mechanical properties of A380 aluminum alloy prepared by squeeze-casting. International Journal of Minerals, Metallurgy and Materials. 2018;25(5):553—564. https://doi.org/10.1007/s12613-018-1602-y

30. Ri E.Н., Prikhodko A.A., Slavinskaya N.A. Structure forming and properties of VAL10 cast alloy modified with cerium and lanthanum. Metallurgiya Mashinostroeniya. 2020;(2):24—30. (In Russ.).