Development of hot deformation rheological model as exemplified by 1424 and V-1461 aluminum-lithium alloys

The article proposes a variant of the rheological model of hot deformation – the law of hyperbolic sine, which, in contrast to the standard one, takes into account not only the strain rate and process temperature, but also the strain ratio. Material constants included in the law of hyperbolic sine are replaced by polynomial functions of the strain ratio with coefficients calculated using the corresponding method developed. The paper describes applications of the rheological model proposed in low-density aluminum-lithium alloys 1424 of the Al–Mg–Li–Zn system and V-1461 of the Al–Cu–Li–Zn system, for which flow curves in the temperature range 400–480 °C and strain rate range 1–60 s–1 up to a strain ratio of 0.6 are defined by physical simulation at the Gleeble 3800 unit. The influence of the initial material state was also investigated – samples were taken from both the ingot and hot-rolled plates. Constants were determined for the rheological model of hot deformation including the Zener–Hollomon parameter and the law of hyperbolic sine for the entire range of stresses and strains. After approximating the dependences of the model parameters on true strains with a 4th degree polynomial law, a rheological model was created that describes the alloy behavior in the temperature-rate range under study. The features of changes in hyperbolic sine law parameters depending on the strain ratio were established. It was shown that, in general, parameters for the cast material are higher than for the rolled one. A comparison between the standard and proposed models showed that the use of the standard model over the entire strain interval leads to too high flow stress values (up to 12 %).

1. Kablov E.N. Materials and chemical technologies for aircraft engineering. Vestnik RAN. 2012. Vol. 82. No. 6. P. 158—167 (In Russ.).

2. Khokhlatova L.V., Kolobnev N.I., Oglodkov M.S., Mikhaylov E.D. Aluminum-lithium alloys for the aircraft. Metallurg. 2012. No. 56 (5-6). P. 31—35 (In Russ.).

3. Gureeva M.A., Grushko O.E., Ovchinnikov V.V. Welded aluminium alloys in the construction of vehicles. Zagotovitel’nye proizvodstva v mashinostroenii. 2009. No. 3. P. 27—41 (In Russ.).

4. Rioja R., Liu J. The evolution of Al—Li base products for aerospace and space applications. Met. Mater. Trans. A. 2012. Vol. 43. P. 3325—3337.

5. Elagin V.I., Zakharov V.V. Modern Al—Li alloys and prospects of their development. Metal Sci. Heat Treat. 2013. Vol. 55. P. 184—190.

6. Kolobnev N.I., Khokhlatova L.V., Antipov V.V. Promising aluminum alloys for aircraft structures. Tekhnologiya legkikh splavov. 2007. No. 2. P. 35—38 (In Russ.).

7. Fridlyander I.N. Aluminum alloys in aircraft in the periods of 1970—2000 and 2001—2015. Met. Sci. Heat Treat. 2001. Vol. 43. P. 6—10.

8. Fridlyander I.N., Hohlatova L.B., Kolobnev N.I., Rendiks K., Tempus G. Thermally stable aluminum-lithium alloy 1424 for application in welded fuselage. Met. Sci. Heat Treat. 2002. Vol. 44. P. 3—8.

9. Setyukov O.A., Kolobnev N.I., Khokhlatova L.B., Oglodkov M.S. Influence of crystallographic orientations on the properties of plates of Al—Li alloys V-1461 and 1424. Tekhnologiya legkikh splavov. 2010. No. 1. P. 100—106 (In Russ.).

10. Milevskaya T.V., Rushits S.V., Tkachenko E.A., Antonov S.M. Deformation behavior of high-strength aluminum alloys under conditions of hot deformation. Aviatsionnye materialy i tekhnologii. 2015. No. 2 (35). P. 3—9 (In Russ.).

11. Khohlatova L.V., Kolobnev N.I., Lukina E.A., Ber L.B. Reduction of anisotropy in the sheets, made of the Al—Mg—Li—Zn-alloy 1424. Tsvetnyye metally. 2013. No. 3. P. 78—81 (In Russ.).

12. Fridlyander I.N., Khokhlatova L.B., Kolobnev N.I., Alekseev A.A., Lukina E.A., Kolesnikova O.K. Constructional alloy 1424 of reduced density of the Al—Mg—Li—Zr—Sc system for welded and riveted structures of aerospace engineering. Tekhnologiya legkikh splavov. 2002. No. 4. P. 20—23 (In Russ.).

13. Khokhlatova L.B., Lukin V.I., Kolobnev N.I., Ioda E.N., Bazeskin A.V., Lavpenchuk V.P., Koshkin V.V., Mezentseva E.A. Prospective aluminum-lithium alloy 1424 for welded structures of aerospace products. Svarochnoe proizvodstvo. 2009. No. 3. P. 7—10 (In Russ.).

14. Erisov Ya.A., Grechnikov F.V., Oglodkov M.S. The influence of fabrication modes of sheets of V-1461 alloy on the structure crystallography and anisotropy of properties. Russ. J. Non-Ferr. Met. 2016. Vol. 57. P. 19—24.

15. Erisov Ya.A., Grechnikov F.V. Physical modelling of hot rolling for low-density alloy of the Al—Mg—Li—Zr—Zn—Sc system. Metallurgist. 2018. Vol. 61. Iss. 9-10. P. 822—829.

16. Longzhou M., Jianzhong C., Xiaobo Z.A. Study on improving the cold-forming property of Al—Mg—Li alloy 01420. Adv. Perf. Mater. 1997. Vol. 4. P. 105—114.

17. Chen Y., Li J., Lu H., Li S., Zheng Z., Zhang Y., Zhang X. Hot deformation behavior of Al—Cu—Li—Mg—Zr alloy containing Zn and Mn. Trans. Nonferr. Met. Soc. China. 2007. Vol. 17. P. s271—s275.

18. Ou, L., Nie Y., Zheng Z. Strain compensation of the constitutive equation for high temperature flow stress of Al—Cu—Li alloy. J. Mater. Eng. Perform. 2014. Vol. 23(1). P. 25—30.

19. Yu X., Zhang Y., Yin D., Yu Z., Li S. Characterization of hot deformation behavior of a novel Al—Cu—Li alloy using processing maps. Acta Metal. Sin. (Eng. Lett.). 2015. Vol. 28(7). P. 817—825.

20. Erisov Ya., Surudin S., Grechnikov F. Hot deformation behavior of Al—Cu—Li—Mg—Zn—Zr—Sc alloy in ascast and hot-rolled condition. Mater. Sci. Forum. 2018. Vol. 920. P. 244—249.

21. Mirzadeh H., Cabrera J.C., Najafizadeh A. Constitutive relationships for hot deformation of austenite. Acta Mater. 2011. Vol. 59. P. 6441—6448.

22. McQueen H.J., Ryan N.D. Constitutive analysis in hot working. Mater. Sci. Eng. A. 2002. Vol. 322. P. 43—63.

23. Kolobnev N.I., Setyukov O.A., Khokhlatova L.B., Oglodkov M.S. The influence of crystallographic orientations on the properties of plates of Al—Li alloys B-1461 and 1424. Tekhnologiya legkikh splavov. 2010. No.1. Р. 100—106 (In Russ.).

24. Lukina E.A., Alekseev A.A., Khokhlatova L.B., Oglodkov M.S. Regular features of formation of main hardening phases in alloys 1424 of the Al—Mg—Li—Zn system and V-1461 of the Al—Cu—Li—Zn—Mg system. Met. Sci. Heat Treat. 2014. Vol. 55(9-10). P. 466—471.

25. Kolobnev N.I., Antipov V.V., Makhsidov V.V., Ryabov D.K., Khokhlatova L.B., Popov V.I., Oglodkov M.S. A method of manufacturing sheets of aluminum alloys: Pat. 2486274 (RF). Declared 10/17/2011. Publ. 06/27/2013. Bull. No. 18 (In Russ.).

26. Antipov V.V., Kolobnev N.I., Khokhlatova L.B. Advancement of Al—Li alloys and of multistage modes of their heat treatment. Met. Sci. Heat Treat. 2014. Vol. 55(9-10). P. 459—465.

27. Kolobnev N.I., Khokhlatova L.B., Oglodkov M.S. Klochkova Yu.Yu. High-strength Al—Cu—Li alloys with increased fracture toughness intended for aircraft structures. Tsvetnye Metally. 2013. Iss. 9. P. 66—71 (In Russ.).

28. Tarasov Yu.M., Vakhromov R.O. Application of aluminium alloys, developed under the guidance of academician I.N. Friedlander, in Russian aviation engineering, in Russian aviation engineering. Tsvetnye Metally. 2013. No. 9. P. 37—39 (In Russ.).

29. Khokhlatova, L.B., Kolobnev N.I., Oglodkov M.S., Lukina E.A., Sbitneva S.V. Change in phase composition in relation to aging regimes and alloy V-1461 semifinished product structure. Met. Sci. Heat Treat. 2012. Vol. 54(5-6). P. 285—289.

30. Semenov Е.I. Forging and stamping: Reference. Vol. 2. Hot stamping. Moscow: Mashinostroyeniye, 1986 (In Russ.).

31. Semenov E.I. Forging and stamping: Reference. Vol. 1. Materials and heating. Equipment. Forging. Moscow: Mashinostroyeniye, 1985 (In Russ.).