Phases changes of the AK12MMgN-18%SiCp composite alloy after severe plastic deformation and annealing

G.R. Khalikova1, G.F. Korznikova1, V.G. Trifonov1
1Institute for Metals Superplasticity Problems of RAS, St. Khalturin Str., 39, Ufa, 450001, Russia
The effect of severe plastic deformation by high pressure torsion (HPT) on the structure of AK12MMgN-18%SiCp composite alloy  was  investigated. The secondary electron image and the mapping to this region on the main elements of alloy after post-HPT annealing at 500°C for 2 hours is shown on the figure.The effect of severe plastic deformation by high pressure torsion (HPT) on the structure of AK12MMgN-18%SiCp composite alloy was investigated. A liquid-forged billet was taken as an initial material. Samples 8 mm in diameter and 0.45 mm in thickness were deformed by torsion in a Bridgman anvil at room temperature up to 5 turns under the pressure of 4 GPa. After deformation the samples were annealed in the temperature range of 300-500°C for 5 minutes. The average area and volume fraction of particles in the initial, HPT-processed and annealed samples were evaluated. The change of the concentration level of a solid solution in the states under study was analyzed. It was shown that HPT led to a fragmentation of particles and a reduction of their average area: silicon particles from 4.4±0.1 to 0.32±0.02 μm2, intermetallic particles from 5.2±2.6 to 0.20±0.02 μm2, and SiC from 37.6±0.9 to 3.9±0.02 μm2. At the same time, a partial dissolution of excess phases occurred that resulted in the formation of a supersaturated solid solution. Post-HPT annealing led to a dissolution of the supersaturated solid solution with a separation of secondary phases of different morphology not typical to the alloy: globular silicon, rod shaped phase enriched by Ni, Si and Fe and a more compact phase containing Si and Cu. The higher the annealing temperature, the more intensive was the process of supersaturated solid solution decomposition and the higher was the volume fraction of silicon and intermetallic particles. Their average area increased with annealing temperature. No changes in the average area and volume fraction of SiC particles during annealings of HPT-processed alloy were observed.
Received: 31 October 2016   Revised: 24 November 2016   Accepted: 24 November 2016
Views: 125   Downloads: 41
Severe plastic deformation: toward bulk production of nanostructured materials / B. S. Altan ed. New York, Nova science publ., Inc. (2006) 612 p.
А. P. Zhilyaev, T. G. Langdon. Prog. Mat. Sci. 53, 893 – 979 (2008), Doi: 10.1016 / j.pmatsci.2008.03.002
A. Azushima, R. Kopp, A. Korhonen, D. Y. Yang, F. Micari, G. D. Lahoti, P. Groche, J. Yanagimoto, N. Tsuji, A. Rosochowski, A. Yanagida. CIRP Annals — Manufacturing Technology, 57, 716 – 735 (2008), Doi:10.1016 / j.cirp.2008.09.005
M. Murayama, Z. Horita, K. Hono. Acta mater. 49, 21 – 29 (2001), Doi:10.1016 / S1359–6454 (00) 00308 – 6
S. Zang, W. Hu, R. Berghammer, G. Gottstein. Acta mater. 58, 6695 – 6705 (2010), Doi:10.1016 / j.actamat.2010.08.034
A. A. Mazilkin, B. B. Straumal, E. Rabkin, B. Baretzky, S. Enders, S. G. Protasova, O. A. Kogtenkova, R. Z. Valiev. Acta Mater. 54, 3933 – 3939 (2006), Doi:10.1016 / j.actamat.2006.04.025
I. G. Brodova, I. G. Shirinkina, A. N. Petrova, O. V. Antonova, V. P. Pilugin. Phys. Met. Metallogr. 111(6), 659 – 667 (2011) (in Russian) [И. Г. Бродова, И. Г. Ширинкина, А. Н. Петрова, О. В. Антонова, В. П. Пилюгин. Физика металлов и металловедение. 111(6), 659 – 667 (2011).]
O. N. Senkov, F. H. Froes, V. V. Stolyarov, R. Z. Valiev, J. Liu. Scripta Materialia, 38(10), 1511 – 1516, 1998, Doi:10.1016 / S1359–6462 (98) 00073 – 6
Г. Р. Халикова, К. С. Швец, В. Г. Трифонов. Письма о Mатериалах, 5(2), 220 – 224 (2015) (in Russian) [G. R. Khalikova, K. S. Shvets, V. G. Trifonov. Letters on materials 5(2),. 220 – 224 (2015)], Doi: 10.22226 / 2410‑3535‑2015‑2‑220‑224
I. G. Brodova, D. V. Bashlikov, M. S. Nikitin, I. G. Shirinkina, T. I. Yablonskikh. Phys. Met. Metallogr. 98(1), 83 – 92 (2004) (in Russian) [И. Г. Бродова, Д. В. Башлыков, М. С. Никитин, И. Г. Ширинкина, Т. И. Яблонских. Физика металлов и металловедение. 98(1), 83 – 92 (2004).]
I. G. Brodova, I. G. Shirinkina, O. V. Antonova, A. V. Chirkova, S. V. Dobaykin. Maltseva. Russian metallurgy (Metally). 4, 25 – 32 (2009) (in Russian) [И. Г. Бродова, И. Г. Ширинкина, О. В. Антонова, А. В. Чиркова, С. В. Добаткин, В. В. Захаров. Деформация и разрушение материалов. 4, 25 – 32 (2009).]
K. Shvets, G. Khalikova, E. Korznikova, V. Trifonov. AIP Conference Proceedings, 1683, 020213 (2015), Doi: 10.1063 / 1.4932903
V. V. Stolyarov, R. Z. Valiev. Nanomaterials by Sever Plastic Deformation. Proceedings of the Conference «Nanomaterials by Sever Plastic Deformation — NANOSPD2». Vienna, Austria. 2002. p. 125 – 130.
Y. Huang, J. D. Robson, P. B. Prangnell. Acta Mater. 58, 1643 – 1657 (2010), Doi:10.1016 / j.actamat.2009.11.008
G. Angella, P. Bassani, A. Tuissi, M. Vedani. Materials Transactions, 45(7), 2282 – 2287 (2004), Doi:10.2320 / matertrans.45.2282
L. Zhen, W. D. Fei, S. B. Kang, H. W. Kim. Materials Science. 32, 1895 – 1902 (1997), Doi: 10.1023 / A:1018569226499
A. Alhamidi, Z. Horita. Materials Science and Engineering A 622, 139 – 145 (2015), Doi: 10.1016 / j.msea.2014.11.009
L. F. Mondolfo. Aluminum alloys: structure and properties. Butterworths. (1976) 971p.
G. R. Khalikova, R. V. Kal’shchikov, K. S. Shvets, V. G. Trifonov. Basic Problems of Material Science. 12(4), 458 – 465 (2015) (in Russian) [Г. Р. Халикова, Р. В. Кальщиков, К. С. Швец, В. Г. Трифонов. Фундаментальные проблемы современного материаловедения. 12(4), 458 – 465 (2015)]
T. N. Lipchin. Structure and properties of nonferrous alloys solidified under pressure, Moscow, Metallurgy (1994) 128p. (in Russian) [Т. Н. Липчин. Структура и свойства цветных сплавов, затвердевших под давлением, М., Металлургия. 1994. 128c.].
N. A. Belov. Phase composition of commercial and perspective aluminum alloys. Moscow, MISIS. (2010) 511 p. (in Russian) [Н. А. Белов. Фазовый состав промышленных и перспективных алюминиевых сплавов. М., МИСиС. 2010. 511с.]