NdFeB esaslı kalıcı manyetik alaşımların manyetik özelliklerine uygulanan ısıl işlemdeki sürenin etkisi

Yıl 2022, Sayı: 40, 138 - 142, 30.09.2022

Muhammed Fatih Kılıçaslan , Yasin Yılmaz , Bekir Akgül

https://doi.org/10.31590/ejosat.1172051

Öz

Mevcut çalışmamızda, hızlı katılaştırma yöntemlerinden biri olan, şerit şeklindeki amorf ve/veya yarı kristalin yapıdaki alaşımların üretilmesinde oldukça yaygın olan ergiyik eğirme (melt spinning) yöntemi kullanılarak, NdFeB esaslı kalıcı mıknatıs şerit alaşımları üretilmiştir. Her bir NdFeB alaşımının üretimi esnasında, ağırlıkça %15 oranında atık mıknatıs, alaşımların kompozisyona dahil edilmiştir. Üretilen kalıcı mıknatıs alaşımları, 710 °C lik ısıl işlem sıcaklığı ve 285 K/s lik çok yüksek ısıtma ve soğutma hızları kullanılmak üzere 5 ve 10 dakikalık sürelerde ısıl işleme tabi tutulmuştur. Aynı sıcaklıkta uygulanan ısıl işlem süresinin, şerit alaşımların manyetik özelliklerine etkisi incelenmiştir. Artan ısıl işlem süresi ile manyetik koerzivite ve maksimum enerji ürünü özelliklerinin dikkate değer bir şekilde değişimiyle sonuçlanırken, doyum manyetizasyonu ve manyetik remenans gibi özelliklerde çok fazla bir değişim meydana gelmemiştir. Açıkça görüldüğü gibi, artan ısıl işlem süresi, manyetik koerzivitede 5030.5 Oe’den 2279.4 Oe’ye doğru sürekli bir düşüşe yol açmışken maksimum enerji ürününde önce 62.02 kJ/m3 ten 103.73 kJ/m3 e doğru çarpıcı bir şekilde artış, daha sonra ise 38.63 kJ/m3 e doğru çarpıcı bir azalma görülmüştür, bu da alaşımın kalıcı mıknatıslığındaki düşüşe işaret etmektedir.

Anahtar Kelimeler

NdFeB, kalıcı mıknatıs, ergiyik eğirme, kalıcı mıknatıslık, ısıl işlem, süre.

Effect of heat treatment time on magnetic properties of NdFeB-based permanent magnetic alloys

Öz

In our current study, NdFeB-based permanent magnet ribbon alloys were produced by using melt spinning method, which is one of the rapid solidification methods and very common in the production of ribbon-shaped, amorphous and/or semi-crystalline alloys. During the production of each NdFeB alloy, 15 wt.% of waste magnet was included in the composition of the alloys. The produced permanent magnet alloys were heat treated for 5 and 10 minutes by using a heat treatment temperature of 710 °C and very high heating and cooling rates of 285 K/s. The effect of the heat treatment time applied at the same temperature on the magnetic properties of the strip alloys was investigated. While the increase in heat treatment time resulted in a remarkable change in magnetic coercivity and maximum energy product properties, there was not much change in the properties such as saturation magnetization and magnetic remenance. As clearly seen, increasing heat treatment time resulted in a continuous decrease in magnetic coercivity from 5030.5 Oe to 2279.4 Oe, maximum energy product first showed a dramatic increase from 62.02 kJ/m3 to 103.73 kJ/m3, and then a dramatic decrease to 38.63 kJ/m3, indicating a decrease in the permanent magnetism of the alloy.

Anahtar Kelimeler

NdFeB, permanent magnet, melt spinning, permanent magnetism, heat treatment, time.

Kaynakça

• Z. Cao, X. Ding, R. Bagheri, A. Ghafar, C. Xu, L. Yang, L. Song, Y. Wen, Z. Song, The deposition , microstructure and properties of Al protective coatings for NdFeB magnets by multi-arc ion plating, Vaccum. 142 (2017) 37–44. https://doi.org/10.1016/j.vacuum.2017.05.003.
• X. Du, T.E. Graedel, Global Rare Earth In-Use Stocks in NdFeB Permanent Magnets, J. Ind. Ecol. 15 (2011) 836–843. https://doi.org/10.1111/j.1530-9290.2011.00362.x.
• D. Brown, B. Ma, Z. Chen, Developments in the processing and properties of NdFeb-type permanent magnets, J. Magn. Magn. Mater. 248 (2002) 432–440.
• C. Chen, Y.L. Huang, Y.F. Yao, X.K. Fu, W. Li, Y.H. Hou, Effects of thermal annealing on improved magnetic properties and microstructure for SmFe 11 Ti alloy, J. Magn. Magn. Mater. 530 (2021) 9–13.
• M. Lv, T. Kong, W. Zhang, M. Zhu, H. Jin, W. Li, Progress on modification of microstructures and magnetic properties of Nd- Fe-B magnets by the grain boundary diffusion engineering, J. Magn. Magn. Mater. 517 (2021). https://doi.org/10.1016/j.jmmm.2020.167278.
• B.B. Straumal, A.R. Kilmametov, A.A. Mazilkin, S.G. Protasova, Amorphization of Nd – Fe – B alloy under the action of high-pressure torsion, Mater. Lett. 145 (2015) 63–66. https://doi.org/10.1016/j.matlet.2015.01.041.
• B.B. Straumal, A.A. Mazilkin, S.G. Protasova, D. V Gunderov, G.A. López, Amorphization of crystalline phases in the Nd – Fe – B alloy driven by the high-pressure torsion, Mater. Lett. 161 (2015) 735–739. https://doi.org/10.1016/j.matlet.2015.09.076.
• Q. Zhou, W. Li, Y. Hong, L. Zhao, X. Zhong, H. Yu, Microstructure improvement related coercivity enhancement for sintered NdFeB magnets after optimized additional heat treatment *, J. Rare Earths. 36 (2018) 379–384. https://doi.org/10.1016/j.jre.2017.11.007.
• Y.J. Wong, H.W. Chang, Y.I. Lee, W.C. Chang, C.H. Chiu, C.C. Mo, Coercivity enhancement of thicker sintered NdFeB magnets by grain boundary di ff usion with low-melting Tb 75 − x Ce x Cu 25 ( x = 0 – 45 ) alloys, J. Magn. Magn. Mater. 515 (2020) 1–6. https://doi.org/10.1016/j.jmmm.2020.167287.
• H.W. Chang, Y.I. Lee, P.H. Liao, W.C. Chang, Scripta Materialia Signi fi cant coercivity enhancement of hot deformed NdFeB magnets by doping Ce-containing ( PrNdCe ) 70 Cu 30 alloys powders, Scr. Mater. 146 (2018) 222–225. https://doi.org/10.1016/j.scriptamat.2017.11.052.
• M.F. Kilicaslan, S.I. Elburni, B. Akgul, The effects of Nb addition on the microstructure and mechanical properties of melt spun Al-7075 alloy, Adv. Mater. s Sci. 21 (2021) 17–19. https://doi.org/10.2478/adms-2021-0008.
• M.F. Kilicaslan, S.I. Elburni, Y. Yilmaz, Effects of b addıtıon on the mıcrostructure and mıcrohardness of melt-spun Al-7075 alloy, Adv. Mater. Sci. 22 (2022) 79–89. https://doi.org/10.2478/adms-2022-0004.
• M.F. Kılıçaslan, Y. Yılmaz, B. Akgül, H. Karataş, C.D. Vurdu, Effect of Fe-Ni Substitution in FeNiSiB Soft Magnetic Alloys Produced by Melt Spinning, Adv. Mater. Sci. 21 (2021) 79–89. https://doi.org/10.2478/adms-2021-0026.
• X.H. Li, Y. Guan, W. Li, J.W. Zhang, X.Y. Zhang, Study of the formation of crystal texture in α-Fe/Nd2Fe14B nanocomposite magnets prepared by controlled melt-spinning, Mater. Lett. 61 (2007) 2728–2730. https://doi.org/10.1016/j.matlet.2006.02.095.
• W.F. Li, T. Ohkubo, K. Hono, M. Sagawa, The origin of coercivity decrease in fine grained Nd-Fe-B sintered magnets, J. Magn. Magn. Mater. 321 (2009) 1100–1105. https://doi.org/10.1016/j.jmmm.2008.10.032.
• K.B. Y. Yang, A. Walton, R. Sheridan, K. Güth, R. GauB, O. Gutfleisch, M. Buchert, B. Steenari, T. V. Gerven, P. T. Jones, REE Recovery from End-of-Life NdFeB Permanent Magnet Scrap : A Critical Review, J. Sustain. Met. (2017) 122–149. https://doi.org/10.1007/s40831-016-0090-4.
• J. Liu, H. Sepehri-Amin, T. Ohkubo, K. Hioki, A. Hattori, T. Schrefl, K. Hono, Effect of Nd content on the microstructure and coercivity of hot-deformed Nd-Fe-B permanent magnets, Acta Mater. 61 (2013) 5387–5399. https://doi.org/10.1016/j.actamat.2013.05.027.
• Z.Y. Zhang, L.Z. Zhao, X.C. Zhong, D.L. Jiao, Z.W. Liu, Phase precipitation behavior of melt-spun ternary Ce2Fe14B alloy during rapid quenching and heat treatment, J. Magn. Magn. Mater. 441 (2017) 429–435. https://doi.org/10.1016/j.jmmm.2017.06.028.
• Y. Lin, B. Wu, S. Li, S. Mao, X. Liu, Y. Zhang, L. Wang, The quantitative relationship between microstructure and mechanical property of a melt spun Al – Mg alloy, Mater. Sci. Eng. A. 621 (2015) 212–217. https://doi.org/10.1016/j.msea.2014.10.047.
• R.E. Simpson, P. Fons, A. V. Kolobov, T. Fukaya, M. Krbal, T. Yagi, J. Tominaga, Interfacial phase-change memory, Nat. Nanotechnol. 6 (2011) 501–505. https://doi.org/10.1038/nnano.2011.96.
• S. Caglar, M.F. Kilicaslan, A. Atasoy, H. Tiryaki, M. Erkovan, S. jik Hong, Effect of heat treatment on magnetic properties of nanocomposite Nd-lean Nd7Fe73B20 ribbons, J. Mater. Sci. Mater. Electron. 32 (2021) 2338–2345. https://doi.org/10.1007/s10854-020-04999-9.
• H. Zhao, H. Liu, J. Su, Influence of heat treatment on microstructures and properties of Nd8Fe78B6Co4 alloy, J. Rare Earths. 24 (2006) 379–381. https://doi.org/10.1016/S1002-0721(07)60406-2.
• H.K. T. Schrefl, J. Fidler, Remanence and coercivity in isotropic nanocrystalline permanent magnets, Phys. Rev. B. 49 (1994).
• V. Swaminathan, P.K. Deheri, S.D. Bhame, R.V. Ramanujan, Novel microwave assisted chemical synthesis of Nd2Fe 14B hard magnetic nanoparticles, Nanoscale. 5 (2013) 2718–2725. https://doi.org/10.1039/c3nr33296a.