Obrabotka Metallov. 2016 no. 1(70)

ОБРАБОТКА МЕТАЛЛОВ № 1 (70) 2016 14 ТЕХНОЛОГИЯ Abstract Due to the improvement of the forms of aircraft, methods of complex surfaces forming using rectangular solid plates and elevated temperatures have become popular. Compared with the production of prefabricated elements, such molding techniques allow saving resources, reducing weight, getting rid of assembly and fitting work on the stage of manufacturing. How different will the fatigue life of pre-deformed at different temperatures and deformation rates products be? The answer to this question is relevant to aerospace industry. Apilot study of the issue is conducted. Fatigue life of pure aluminum alloy (Al-Zn-Mg-Cu), depending on temperature of pre-deformation and strain rate is set. Experimental modeling of fatigue life of pure aluminum alloy samples is made. Three series of samples previously plastically deformed at different strain rates (1 - at room temperature, 2 – artificial aging temperature and 3 – at the annealing temperature) were used. Plastically deformed samples were heat-treated using the mode T2 in accordance with the production instruction 1.2.699–2007 PI. The effect of the reverse creep at relaxation is shown. This effect should be considered when designing the formation of large structural components at elevated temperatures. The number of cycles to failure at regular loading depends on temperature and deformation rate. Pure aluminum alloy (Al-Zn-Mg-Cu) fatigue resistance does not decrease after a pre-deformation at the annealing temperature. Keywords: processing technique, forming, strain rate, experiment, durability, aluminum alloy, creep, fatigue. DOI: 10.17212/1994-6309-2016-1-6-15 References 1. Kolobnev N.I., Khokhlatova L.B., Antipov V.V. Perspektivnye alyuminievye splavy dlya samoletnykh kon- struktsii [Advanced aluminium-lithium alloys for aircraft structures]. Tekhnologiya legkikh splavov – Technology of light alloys , 2007, no. 2, pp. 35–38. 2. Prasad N.E., Gokhale A., Wanhil R.J.H., eds. Aluminum-lithium alloys: processing, properties, and applica- tions. 1 st ed. Elsevier Publ., Butterworth-Heinemann, 2013. 608 p. ISBN 978-0-12-401698-9 3. Lumley R., ed. Fundamentals of aluminium metallurgy: production, processing and applications. 1 st ed. Ox- ford, Woodhead Publ., 2011. 864 p. ISBN 978-184569-654-2 4. Fridlyander I.N. Sovremennye alyuminievye, magnievye splavy i kompozitsionnye materialy na ikh osnove [Modern aluminum, magnesium alloys, and composites developed on their base]. VIAM/2002-203509. Available at: http://viam.ru/public/files/2002/2002-203509.pdf (accessed 15.02.2016) 5. OST 1 90026–80. Splavy alyuminievye deformiruemye povyshennoi chistoty. Marki [Industry standard 1 90026–80. Premium aluminium wrought alloys. Grades]. Moscow, VIAM Publ., 1980. 13 p. (In Russian) 6. Miodushevskii P.V., Raevskaya G.A., Sosnin O.V. Sposob formoobrazovaniya detalei i ustroistvo dlya ego osushchestvleniya [A method of forming parts and device for its realization]. Patent RF, no. 2056197, 1996. 7. Lee W.S., Sue W.C., Lin C.F., Wu C.J. Effect of aging on high strain rate and high temperature proper- ties of 7075 aluminium alloy. Materials Science and Technology , 1999, vol. 15, iss. 12, pp. 1379–1386. doi: 10.1179/026708399101505509 8. Quan G., Liu K., Zhou J., Chen B. Dynamic softening behaviors of 7075 aluminum alloy. Transactions of Nonferrous Metals Society of China , 2009, no. 19, pp. 537–541. 9. Hidalgo-Manrique P., Cepeda-Jiménez C.M., Orozco-Caballero A., Ruano O.A., Carreño F. Evolution of the microstructure, texture and creep properties of the 7075 aluminium alloy during hot accumulative roll bonding. Ma- terials Science and Engineering: A , 2014, vol. 606, pp. 434–442. doi: 10.1016/j.msea.2014.03.105 10. Naser T.S.B., Krallics G. Mechanical behavior of multiple-forgedAl 7075 aluminum alloy. Acta Polytechnica Hungarica, 2014, vol. 11, no. 7, pp. 103–117. doi: 10.12700/APH.11.07.2014.07.7 11. Tsvelodub I.Yu. Postulat ustoichivosti i ego prilozheniya v teorii polzuchesti metallicheskikh materialov [The postulate of sustainability and its application to the creep theory of metallic materials]. Novosibirsk, Lavrentyev In- stitute of Hydrodynamics Publ., 1991. 201 p. 12. Naumenko K., Altenbach H. Modeling of creep for structural analysis . Berlin, Heidelberg, Springer Publ., 2007. 230 p. ISBN 978-3-540-70834-6. doi: 10.1007/978-3-540-70839-1 13. Altenbach H., Matsuda T., Okumura D., eds. From creep damage mechanics to homogenization methods: a Liber Amicorum to celebrate the birthday of Nobutada Ohno . Cham, Springer International Publ., 2015. 601 p. ISBN 978-3-319-19439-4. doi: 10.1007/978-3-319-19440-0