Abstract
Grain refinement is a satisfying method to enhance the comprehensive performance of Mg alloys, and using grain refiners to improve the quality of Mg castings has become a common practice in the current casting industry. In this study, the effects of Al-CeO2-Mg grain refiner addition on microstructure, cast fluidity, and mechanical properties of AZ91 alloy were systemically investigated by OM, SEM, DSC, TEM, sand Archimedean spiral mold fluidity test, and tensile test. The results show that the Al-CeO2-Mg grain refiner has a remarkable effect on as-cast AZ91 alloy including notable grain refinement, enhancement of cast fluidity, and improvement of tensile properties. The average grain size of AZ91 alloy is refined by 63% with 1.0wt.% Al-CeO2-Mg grain refiner. Meanwhile, the casting flow length of the as-cast AZ91 alloy is increased from 332 mm to 440 mm. The improvement of cast fluidity is attributed to the decreased liquidus temperature, shortening of solid-liquid two-phase temperature range, and refinement of microstructure.
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Satya Prasad S V, Prasad S B, Verma K, et al. The role and significance of magnesium in modern day research-A review. Journal of Magnesium and Alloys, 2022, 10: 1–60.
Wu H F, Hu W X, Ma S B, et al. Effect of Ce on microstructure and mechanical properties of Mg-Zn-Ce magnesium alloys. China Foundry, 2023, 20(4): 271–279.
Wang Q D, Lu Y Z, Zeng X Q, et al. Study on the fluidity of AZ91+xRE magnesium alloy. Materials Science and Engineering: A, 1999, 271(1): 109–115.
Li H N, Wang K, Xua G P, et al. Nanoparticle-induced growth behavior of primary α-Mg in AZ91 alloys. Materials & Design, 2020, 196: 109146.
Weiler J P. Exploring the concept of castability in magnesium die-casting alloys. Journal of Magnesium and Alloys, 2021, 9(1): 102–111.
Zhou Y, Mao P L, Wang Z, et al. Experimental investigation and simulation assessment on fluidity and hot tearing of Mg-Zn-Cu system alloys. Journal of Materials Processing Technology, 2021, 297: 117259.
Dahle A K, Arnberg L. Development of strength in solidifying aluminum alloys. Acta Materialia, 1997, 45(2): 547–559.
Kang B K, Sohn I. Effects of Cu and Si contents on the fluidity, hot tearing, and technical properties of Al-Cu-Si alloys. Metallurgical and Materials Transactions, 2018, 49: 5137–5145.
Fu Y, Wang H, Zhang C, et al. Effects of minor Sr additions on the as-cast microstructure, fluidity and mechanical properties of Mg-4.2Zn-1.7RE-0.8Zr-0.2Ca (wt.%) alloy. Materials Science and Engineering: A, 2018, 723: 118–125.
Turen Y. Effect of Sn addition on microstructure, mechanical and casting properties of AZ91 alloy. Materials & Design, 2013, 49: 1009–1015.
Kwon Y D, Lee Z H. The effect of grain refining and oxide inclusion on the fluidity of Al-4.5Cu-0.6Mn and A356 alloys. Materials Science and Engineering: A, 2003, 360(1–2): 372–376.
Ali Y, Qiu D, Jiang B, et al. Current research progress in grain refinement of cast magnesium alloys: A review article. Journal of Alloys and Compounds, 2015, 619: 639–651.
Kimura R, Hatayama H, Shinozaki K, et al. Effect of grain refiner and grain size on the susceptibility of Al-Mg die casting alloy to cracking during solidification. Journal of Materials Processing Technology, 2009, 209(1): 210–219.
Davis T A, Bichler L. Effect of Al-Ti master alloy on the grain refinement and hot tearing of AZ91 Mg alloys. Journal of Materials Engineering and Performance, 2023, 6(32): 2577–2586.
Han J H, Liu Z D, Jia Y, et al. Effect of TiB2 addition on microstructure and fluidity of cast TiAl alloy. Vacuum, 2020, 174: 109210.
Davis T A, Bichler L. Novel fabrication of a TiB2 grain refiner and its effect on reducing hot tearing in AZ91D magnesium alloy. Journal of Materials Engineering and Performance, 2018, 27(9): 4444–4452.
Fan W X, Bai Y, Zuo G L, et al. Preparation of Al-CeO2-Mg grain refiner for AZ31 Mg alloy via a novel direct melt reaction process. Materials Letters, 2022, 325: 132881.
Fu Y, Wang H, Liu X T, et al. Effect of calcium addition on microstructure, casting fluidity and mechanical properties of Mg-Zn-Ce-Zr magnesium alloy. Journal of Rare Earths, 2017, 35(5): 503–509.
Chen T J, Wang R Q, Ma Y, et al. Grain refinement of AZ91D magnesium alloy by Al-Ti-B master alloy and its effect on mechanical properties. Materials & Design, 2012, 34: 637–648.
Fan W X, Bai Y, Zuo G L, et al. The control of NbB2 particles in Al-NbB2 master alloy and its effect on grain refinement of AZ91 magnesium alloy. Materials Science and Engineering: A, 2022, 854: 143808.
Liu X T, Hao H. The influence of carbon content on Al-Ti-C master alloy prepared by the self-propagating high-temperature synthesis in melt method and its refining effect on AZ31 alloy. Journal of Alloys and Compounds, 2015, 623: 266–273.
Fan W X, Bai Y, Zuo G L, et al. Enhanced grain refinement and mechanical properties of AZ91 alloy by a novel Al-5.1V-2.3B refiner containing VB2 and VB particles. Materials & Design, 2023, 225: 111474.
Fan Z Y, Gao F, Jiang B, et al. Impeding nucleation for more significant grain refinement. Scientific Reports, 2020, 10: 9448.
Karakulak E. A review: Past, present and future of grain refining of magnesium castings. Journal of Magnesium and Alloys, 2019, 7(3): 355–369.
Liu B S, Wu Z, Zhang Y Z, et al. Simultaneously enhanced the strength and ductility in Mg17Al12 intermetallic compound with Ce addition. Materials Letters, 2022, 320: 132324.
Greer A L. Overview: Application of heterogeneous nucleation in grain-refining of metals. The Journal of Chemical Physics, 2016, 145(21): 211704.
Ravi K R, Pillai R M, Amaranatha K R, et al. Fluidity of aluminum alloys and composites: A review. Journal of Alloys and Compounds, 2008, 456(1–2): 201–210.
Dahle A K, Arnberg L. The effect of grain refinement on the fluidity of aluminum alloys. Materials Science Forum, 1996, 217–222: 259–264.
Li P, Hou D H, Han E H, et al. Solidification of Mg-Zn-Zr alloys: Grain growth restriction, dendrite coherency and grain size. Acta Metallurgica Sinica (English Letters), 2020, 33(11): 1477–1486.
Cui J, Luo T J, Li Y J, et al. Fluidity, microstructure, and tensile properties of sub-rapidly solidified Mg-6Al-4Zn-xSn (x=0, 0.6, 1.2, 1.8) alloy. Acta Metallurgica Sinica (English Letters), 2021, 34(9): 1265–1276.
Yang M B, Pan F S. Effects of Sn addition on as-cast microstructure, mechanical properties and casting fluidity of ZA84 magnesium alloy. Materials & Design, 2010, 31(1): 68–75.
Fan W X, Bai Y, Li J H, et al. Grain refinement of Mg-Al alloys by a new Al-4.1V-1.7B refiner containing sole VB2 particles. Journal of Materials Engineering and Performance, 2023, 32(2): 761–772.
Xiao P, Gao Y M, Xu F X, et al. An investigation on grain refinement mechanism of TiB2 particulate reinforced AZ91 composites and its effect on mechanical properties. Journal of Alloys and Compounds, 2019, 780: 237–244.
Dahle A K, Karlsen S, Arnberg L. Effect of grain refinement on the fluidity of some binary Al-Cu and Al-Mg alloys. lnternational Journal of Cast Metals Research, 1996, 9: 103–112.
Flemings M C, Mollard F R, Taylor H F. Mould variables influence on fluidity of aluminum. AFS Transactions 1961, 69: 566–576.
Malekan M, Shabestari S G. Effect of grain refinement on the dendrite coherency point during solidification of the A319 aluminum alloy. Metallurgical and Materials Transactions: A, 2009, 40(13): 3196–3203.
Wang J J, Niu L, Zhang Y L, et al. Is Mg17Al12 ductile or brittle? A theoretical insight. Journal of Magnesium and Alloys, 2023, 11: 936–944.
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This work was supported by the National Natural Science Foundation of China (52171030) and the National Key Research and Development Program of China (2018YFA0702903).
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Prof. Hai Hao is an EBM of CHINA FOUNDRY. He was not involved in the peer-review or handling of the manuscript. The authors have no other competing interests to disclose.
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Wen-xue Fan
Male, born in 1994, Ph. D. His research interests mainly focus on fine grain strengthening of magnesium alloys.
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Fan, Wx., Bai, Y., Hao, H. et al. Al-CeO2-Mg refiner on grain refinement, cast fluidity and mechanical properties of AZ91 alloy. China Foundry (2024). https://doi.org/10.1007/s41230-024-3102-1
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DOI: https://doi.org/10.1007/s41230-024-3102-1