Application of Thermodynamic Modeling for Optimization of the Composition of Nanostructured Low-Alloyed Hafnium Bronzes by High-Pressure Torsion

Abstract:

According to the results of thermodynamic calculations, it has been determined that the usage of alloys with Hf content near to its maximum possible value solubility in the copper matrix is not appropriate. It is more appropriate to use alloy compositions with lower Hf content. With the help of calculations and analysis of experimental data, it has been established that in order to ensure the thermal stability of SPD-formed structures it is sufficient to obtain a concentration of dissolved in copper matrix Hf of about 0.01 at.%. It has also been shown that the average grain size formed by the SPD is a determining factor in the strength properties of these alloys; an increasing Hf concentration in the copper matrix is not always a condition for higher hardness values. However, higher concentrations of dissolved hafnium in the copper matrix will determine the higher mechanical characteristics of precipitation hardening of the alloys after heat treatment.

• Periodical: Defect and Diffusion Forum (Volume 410)
• Pages: 85-90
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.410.85
• Online since: August 2021
• Authors: Alexey V. Stolbovsky*, Polina Y. Shirshova
• Keywords: CALPHAD, Hafnium Bronze, High-Pressure Torsion, Nanostructure, Nanostructuring, Severe Plastic Deformation, Thermal Stability

References

[1] D. Shangina, J. Gubicza, E. Dodony, N. Bochvar, P. Straumal, N. Tabachkova and S. Dobatkin, Improvement of strength and conductivity in Cu-alloys with the application of high pressure torsion and subsequent heat-treatments, J. Mater. Sci. 49 (2014) 6674-6681.

DOI: 10.1007/s10853-014-8339-4

[2] R.Z. Valiev, A.P. Zhilyaev, T.G. Langdon, Bulk Nanostructured Materials: Fundamentals and Applications, TMS, Wiley, Hoboken, New Jersey, USA, (2014).

[3] A.M. Glezer, E.V. Kozlov, N.A. Koneva, N.A. Popova, I.A. Kurzina, Plastic Deformation of Nanostructured Materials, 1st Edition, CRC Press, Taylor & Francis Group, UK, (2017).

DOI: 10.1201/9781315111964

[4] V.V. Popov, A.V. Stolbovkiy, E.N. Popova, V.P. Pilyugin, Structure and thermal stability of Cu after severe plastic deformation, Defect and Diffusion Forum. 297-301 (2010) 1312-1321.

DOI: 10.4028/www.scientific.net/ddf.297-301.1312

[5] A.V. Stolbovsky, V.V. Popov, E.N. Popova, V.P. Pilyugin, Structure, thermal stability, and state of grain boundaries of copper subjected to high-pressure torsion at cryogenic temperatures, Bull. Russ. Acad. Sci. Phys. 78 (2014) 908-916.

DOI: 10.3103/s1062873814090299

[6] D.V. Shangina, N.R. Bochvar and S.V. Dobatkin, The effect of alloying with hafnium on the thermal stability of chromium bronze after severe plastic deformation, J. Mater. Sci. 47 (2012) 7764-7769.

DOI: 10.1007/s10853-012-6525-9

[7] S.V. Dobatkin, N.R. Bochvar and D.V. Shangina, Aging Processes in ultrafine-grained low-alloyed bronzes subjected to equal channel angular pressing, Adv. Eng. Mater. 17 (2015) 1862-1868.

DOI: 10.1002/adem.201500099

[8] P.R. Subramanlan and D.E. Laughlin, The Cu-Hf (Copper-Hafnium) System, J. Phase Equilib. 9 (1988) 51-56.

[9] Zi-Kui Liu, Computational thermodynamics and its applications, Acta Mater. 200 (2020) 745-792.

[10] D. Liang and Y. Liu, Reevaluation of the Cu–Hf binary system, J. Alloy. Compd. 426 (2006) 101-105.

[11] M.A. Turchanin and P.G. Agraval, Thermodynamic assessment of the copper−hafnium system, Powder Metall. Met. Ceram. 47 (2008) 223-233.

DOI: 10.1007/s11106-008-9008-4

[12] Y. Zhong, A. Saengdeejing, L. Kecskes, B. Klotz and Zi-Kui Liu, Experimental and computational studies of the Cu–Hf binary system, Acta Mater. 61 (2013) 660-669.

DOI: 10.1016/j.actamat.2012.10.014

[13] N.R. Bochvar, O.V. Rybalchenko, D.V. Shanginaa and S.V. Dobatkin, Effect of equal-channel angular pressing on the precipitation kinetics in CuCr-Hf alloys, Mater. Sci. Eng. A. 757 (2019) 84-87.

DOI: 10.1016/j.msea.2019.04.073

[14] A. Stolbovsky, V. Popov and R. Falahutdinov, Effect of Hf doping of commercially pure copper on evolution of its microstructure under high pressure torsion, Solid State Phenomena. 299 (2020) 424-429.

DOI: 10.4028/www.scientific.net/ssp.299.424

[15] V.V. Popov, E.N. Popova, A.V. Stolbovsky, R.M. Falahutdinov, S.A. Murzinova, E.V. Shorokhov and K.V. Gaan, Influence of the initial treatment on the structure of hafnium bronze upon high-speed pressing, Phys. Met. Metallogr. 121 (2020) 452-459.

DOI: 10.1134/s0031918x20050117

[16] D.V. Shan'gina, N.R. Bochvar and S.V. Dobatkin, Structure and properties of Cu-Cr alloys subjected to shear under pressure and subsequent heating, Russian Metallurgy (Metally). 2010 (2010) 1046-1052.

DOI: 10.1134/s0036029510110091

[17] V.V. Popov, E.N. Popova, A.V. Stolbovsky, R.M. Falahutdinov, Evolution of the structure of Cu–1% Sn bronze under high pressure torsion and subsequent annealing, Phys. Met. Metallogr. 119 (2018) 358-367.

DOI: 10.1134/s0031918x18040154

[18] W. Smith and J. Hashemi, Foundations of Materials Science and Engineering, 5th edition, McGraw-Hill Education, UK, (2009).

[19] C.E. Carlton and P.J. Ferreira, What is behind the inverse Hall–Petch effect in nanocrystalline materials?, Acta Mater. 55 (2007) 3749-3756.

DOI: 10.1016/j.actamat.2007.02.021

[20] A. Stolbovsky, V. Popov and R. Falahutdinov, The structure of annealed hafnium bronze subjected to severe plastic deformation by high pressure torsion, IOP Conf. Series: Mater. Sci. and Eng. 969 (2020) 012087.

DOI: 10.1088/1757-899x/969/1/012087