Low-temperature sintering and hot rolling of hard powder magnetic Fe-Cr-Co alloy

A.S. Ustyuhin, A.B. Ankudinov, V.A. Zelenskii, I.M. Milyaev, M.I. Alymov

Abstract

In present work a method for obtaining technically useful Fe-26%Cr-16%Co-2%Mo-2%W hard magnetic alloy from powder raw materials is proposed. The distinctive feature of the method is the lowered sintering temperature of powder compacts (1100 - 1200 °C).In present work a method for obtaining technically useful Fe-26 %Cr-16 %Co-2 %Mo-2 %W hard magnetic alloy from powder raw materials is proposed. The distinctive feature of the method is the lowered sintering temperature of powder compacts (1100 – 1200°C). Sintered blanks are subjected to a hot rolling process at 1150°С. Magnetic material produced by the proposed method has relative density about 97 – 98 %. Magnetic properties of alloy sintered at 1200°C (Br = 1,2 T, Hcb = 51kA / m, (BH)max = 30 kJ / m3) are on the same level as for alloys obtained by powder metallurgy methods with sintering temperatures higher than 1300°C and their cast analogs. At the same time low magnetic properties were obtained on alloy sintered at 1100°C with the following hot rolling. Using EDX analysis and X-ray phase analysis it is established that this is due to the presence of significant fraction of non-magnetic γ-phase in the samples. Apparently under these sintering conditions the redistribution of alloy components does not succeed. Tensile strength tests of the hot-rolled alloy after heat treatment showed a significant effect of sintering temperature on the samples strength. The tensile strength was higher for the samples sintered at 1100°C (700 – 930 MPa) as compared to the samples sintered at 1200°C (520 – 590 MPa). Investigation of the samples microstructure showed that alloy sintered at 1200°C has a more coarse-grained structure. Apparently this is a cause of the tensile strength reduction.

References (13)

1.
Szymura S., Sojka L. Journal of Materials Science. 1979, № 14, p. 1890 – 1892, doi:10.1007 / BF00551028
2.
Kozlov Yu. I., Rakitina Z. A., Balabanova S. V. Metal Science and Heat Treatment. 1985, Vol. 27 (4), p. 293 – 295, doi:10.1007 / BF00652097
3.
Kubota T., Wakui G., Itakagi M. IEEE Transactions on Magnetics. 1998. Vol. 34 (6). p. 3888 – 3896, doi:10.1109 / 20.728299
4.
Artamonov E. V., Libman M. A., and Rudanovskii N. N. Steel in Translation. 2007, Vol. 37, № 6, p. 547 – 551, doi:10.3103 / S0967091207060186
5.
Libman M. A. Materialovedenie [Material science]. 2010, № 9, p. 58 – 64. (in Russian). [Либман М. А. Материаловедение. 2010. № 9. с. 58 – 64.]
6.
Zhen Liang, Sun Xue-yin, Xu Cheng-yan, Gao Run-sheng, Xu Ren-gen, Qin Lu-chang. Transactions of Non-ferrous Metals Society of China. 2007. Vol. 17. p. 346 – 350, doi:10.1016 / S1003–6326 (07) 60096‑X
7.
Belozerov, E. V., Mushnikov N. V., Ivanova G. V. et. al. The Physics of Metals and Metallography. 2012, Vol. 113, № 4, p. 319 – 325, doi:10.1134 / S0031918X12040023
8.
Green M. L., Sherwood R. C., Wong C. C. J. Appl. Phys. 1982, Vol. 53, №.3, p. 2398 – 2400, doi:10.1063 / 1.330824
9.
Shatsov, A. A. Metal Science and Heat Treatment., 2004, vol. 46, p. 152 – 155, doi:10.1023 / B:MSAT.0000036668.48856.02
10.
Alymov M. I., Ankudinov A. B., Zelenskiy V. A., Milyaev I. M., Yusupov V. S., Ustyuhin A. S. Phizika I khimiya obrabotki materialov. [Physics and chemistry of materials treatment] 2011. № 3. p. 34 – 38. (in Russian) [Алымов М. И., Анкудинов А. Б., Зеленский В. А., Миляев И. М., Юсупов В. С., Устюхин А. С. Физика и химия обработки материалов. 2011. № 3. с. 34 – 38.]
11.
Schiller S., Heisig U. Panzer S. Electron Beam Technology. New York.: Wiley & Sons, 1982, 508 p.
12.
Ustyuhin A. S., Alymov M. I., Milyaev I. M. Letters on materials. 2014. Vol. 4, № 1. p. 59 – 61. (in Russian) [Устюхин А. С., Алымов М. И., Миляев И. М. Письма о материалах. 2014. Т. 4, № 1. с. 59 – 61.] doi:10.22226 / 2410‑3535‑2014‑1‑59‑61
13.
Ustyuhin A. S., Alymov M. I., Krishenik P. М., Levinsky Y. V., Rogachev S. А. Phizika I khimiya obrabotki materialov [Physics and chemistry of materials treatment]. 2016, № 3, p. 46 – 51. (in Russian) [Устюхин А. С., Алымов М. И., Кришеник П. М., Левинский Ю. В., Рогачев С. А. Физика и химия обработки материалов. 2016, № 3, с. 46 – 51.]