All-Russian Scientific Research Institute of Aviation Materials, State Research Center of the Russian Federation, Moscow, Russia

R. O. Vakhromov, Head of Laboratory, e-mail: admin@viam.ru
E. A. Tkachenko, Head of a Sector
O. I. Popova, First Category Engineer

One of the main trends for improvement of complex of characteristics of Al – Zn – Mg – Cu-alloys are optimization of the chemical composition by microadditives and impurities and application of multi-staged heat treatment. This paper describes the effect of impurities (Fe, Si), main alloying elements (Zn, Mg, Cu), microadditives of Zr, Sc, Ag on structure, mechanical properties and corrosion resistance of forgings fabricated in FSUE “VIAM”. It is shown, that the addition of 0.1–0.2 % (mas.) Ag and the limitation of impurities of Fe and Si less than 0.1% (mas.) in wrought semiproducts of Al – Zn – Mg – Cu-alloys lead to improvement of tensile strength, elongation, fracture toughness and fatigue life. During the mechanical treatment of forged semiproducts high level of residual stress in forgings after water quenching because of high temperature gradient leads to shape distortion. One of methods of residual stress reduction is application of quenching with low speed (in hot water). However, decreasing of quenching speed can lead to increasing of anisotropy of mechanical properties depending of thickness. The paper shows results of investigation of Al – Zn – Mg – Cu-alloy forgings with different Zn/Mg ratio after quenching in cold and hot water. It is found that the best complex of properties and the reduced level of residual stress shows forging with Zn/Mg = 4.3. Results show the possibility of application of forged semiproducts of Al – Zn – Mg – Cu-alloys with improved characteristics instead of AK6 and V93 alloys.

1. Fridlyander I. N. Vysokoprochnye deformiruemye alyuminievye splavy (High-strength deformated aluminium alloys). Moscow : Oborongiz, 1960. 290 p.
2. Fridlyander I. N., Senatorova O. G., Tkachenko E. A. Vysokoprochnye splavy sistemy Al – Zn – Mg – Cu (Highstrength alloys of Al – Zn – Mg – Cu-system). Moscow : Mashinostroenie, 2001. Vol. 2/3. pp. 94–128.
3. Fridlyander I. N. Tekhnologiya legkikh splavov — Technology of light alloys. 2002. No. 4. pp. 12–17, 28–37.
4. Каigorodova L. I., Selnikhina E. I., Тkаchenko Е. А., Senatorovа О. G. Fizika metallov i metallovedenie — Fhysics of metals and metallography. 1996. Vol. 81, iss. 5. pp. 78–86.
5. Polmer I. J. Proceedings of ICAA6. Toyohashi (Japan). 1998. Vol. 1. pp. 75–86.
6. Fridlyander I. N., Dobromislov A. V., Tkachenko E. A., Senatorova O. G. Metallovedenie i termicheskaya obrabotka metallov — Metal Science and Heat Treatment. 2005. No. 7. pp. 17–23.
7. Antipov V. V., Senatorova O. G., Tkachenko E. A., Vakhromov R. O. Metallovedenie i termicheskaya obrabotka metallov — Metal Science and Heat Treatment. 2011. No. 9. pp. 17–23.
8. Antipov V. V. Aviatsionnye materialy i tekhnologii : yubileynyy nauchno-tekhnicheskiy sbornik Vserossiyskogo nauchnoissledovatelskogo instituta aviatsionnykh materialov (Aviation materials and technologies : anniversary scientific and technical collection of All-Russian Scientific Research Institute of Aviation Materials). 2012. pp. 157–167.
9. Antipov V. V., Senatorova O. G., Tkachenko E. A., Vakhromov R. O. Aviatsionnye materialy i tekhnologii : yubileynyy nauchno-tekhnicheskiy sbornik Vserossiyskogo nauchno-issledovatelskogo instituta aviatsionnykh materialov (Aviation materials and technologies : anniversary scientific and technical collection of All-Russian Scientific Research Institute of Aviation Materials). 2012. pp. 167–183.