Influence of introducing Zr, Ti, Nb and Ce elements on externally solidified crystals and mechanical properties of high-pressure die-casting Al–Si alloy

EXECUTIVE SUMMARY

이 연구는 자동차 산업에서 널리 쓰이는 고압 다이캐스팅(HPDC) AlSi10MnMg 합금의 열처리 없이 고강도 및 인성을 얻기 위한 새로운 합금 개발에 초점을 맞추고 있습니다. 기존 합금은 열처리 과정에서 변형이 발생하고, 다이캐스팅 과정에서 생성되는 외부 응고 결정(ESCs)이 기계적 성질을 저하시키는 문제가 있습니다.

이 연구에서는 AlSi9Mn 합금을 기본으로 하여 Zr, Ti, Nb, Ce를 첨가하여 ESCs의 크기와 형상, 그리고 기계적 성질에 미치는 영향을 조사했습니다. 주요 결과는 다음과 같습니다:

  • Ti 첨가: ESCs 크기와 기공률을 증가시켜 오히려 좋지 않은 영향을 미침
  • Nb 첨가: ESCs 크기를 줄이고 기공률을 감소시켜 긍정적인 영향을 미침
  • Zr, Ti 첨가: 큰 크기의 Al3(Zr,Ti) 상을 형성하여 기계적 성질을 저하시킴
  • Ce 첨가: 독성 효과로 인해 기계적 성질을 더욱 저하시킴

결론적으로, 이 연구는 Ti와 Ce 첨가는 HPDC Al-Si 합금의 기계적 성질에 부정적인 영향을 미치며, Nb 첨가는 ESCs 미세화와 기공률 감소에 효과적임을 보여줍니다. 따라서 열처리 없이 고강도 및 인성을 확보하기 위해서는 합금 원소 첨가에 대한 신중한 접근이 필요함을 시사합니다.

Influence of introducing Zr, Ti, Nb and Ce elements on externally solidified crystals and mechanical properties of high-pressure die-casting Al–Si alloy

Keywords : aluminium alloy high

Junjie Li, Wenbo Yu, Zhenyu Sun, Weichen Zheng, Liangwei Zhang, Yanling Xue, Wenning Liu & Shoumei Xiong 

Abstract

High pressure die casting (HPDC) AlSi10MnMg alloy castings are widely used in the automobile industry. Mg can optimize the mechanical properties of castings through heat treatment, while the release of thermal stress arouses the deformation of large integrated die-castings. Herein, the development of non-heat treatment Al alloys is becoming the hot topic. In addition, HPDC contains externally solidified crystals (ESCs), which are detrimental to the mechanical properties of castings. To achieve high strength and toughness of non-heat treatment die-casting Al–Si alloy, we used AlSi9Mn alloy as matrix with the introduction of Zr, Ti, Nb, and Ce. Their influences on ESCs and mechanical properties were systematically investigated through three-dimensional reconstruction and thermodynamic simulation. Our results reveal that the addition of Ti increased ESCs’ size and porosity, while the introduction of Nb refined ESCs and decreased porosity. Meanwhile, large-sized Al3(Zr,Ti) phases formed and degraded the mechanical properties. Subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.

References

  1. L. Zhu, F. Qiu, Q. Zou, et al., Multiscale design of α-Al, eutectic silicon and Mg2Si phases in Al–Si–Mg alloy manipulated by in situ nanosized crystals, Mater. Sci. Eng. A, 802(2021), art. No. 140627.
  2. W.J. Liu, Y.D. Li, Z.X. Song, X.M. Luo, H.K. Yang, and G.L. Bi, Effect of trace Sr+Ce compound modification on microstructure, thermal conductivity and mechanical properties of AlSi10MnMg alloy, Chin. J. Nonferrous Met., 32(2022), No. 2, p. 332.Google Scholar 
  3. X.Y. Jiao, Y.X. Liu, J. Wang, et al., The microstructure characteristics and fracture behavior of the polyhedral primary iron-rich phase and plate-shaped eutectic iron-rich phase in a high-pressure die-cast AlSi10MnMg alloy, J. Mater. Sci. Technol., 140(2023), p. 201.Article CAS Google Scholar 
  4. X.Y. Jiao, P.Y. Wang, Y.X. Liu, et al., Fracture behavior of a high pressure die casting AlSi10MnMg alloy with varied porosity levels, J. Mater. Res. Technol., 25(2023), p. 1129.Article CAS Google Scholar 
  5. J.M. Sanchez, M. Arribas, H. Galarraga, M. Garcia de Cortazar, M. Ellero, and F. Girot, Effects of Mn addittion, cooling rate and holding temperature on the modification and purification of iron-rich compounds in AlSi10MnMg(Fe) alloy, Heliyon, 9(2023), No. 2, art. No. e13005.
  6. Y. Liu, B.H. Duan, G.Y. Chen, et al., Development history and future prospect of die cast aluminum alloy, Mater. Rep., 37(2023), No. Z2, art. No. 23030025.
  7. A.A. Luo, A.K. Sachdev, and D. Apelian, Alloy development and process innovations for light metals casting, J. Mater. Process. Technol., 306(2022), art. No. 117606.
  8. W.P. Liu, C.H. Zhao, T. Peng, Z.W. Zhang, and A.P. Wan, Simulation-assisted multi-process integrated optimization for green-telligent aluminum casting, Appl. Energy, 336(2023), art. No. 120831.
  9. Y.F. Zhang, X.W. Song, H. Wu, et al., Development and application of integrated die casting technology in shock tower of body, Foundry, 72(2023), No. 4, p. 437.Google Scholar 
  10. X.P. Niu, B.H. Hu, I. Pinwill, and H. Li, Vacuum assisted high pressure die casting of aluminium alloys, J. Mater. Process. Technol., 105(2000), No. 1–2, p. 119.Article Google Scholar 
  11. H.X. Cao, C.C. Wang, Q.Y. Shan, et al., Kinetic analysis of pore formation in die-cast metals and influence of absolute pressure on porosity, Vacuum, 168(2019), art. No. 108828.
  12. Y.J. Zhang, E. Lordan, K. Dou, S.H. Wang, and Z.Y. Fan, Influence of porosity characteristics on the variability in mechanical properties of high pressure die casting (HPDC) AlSi7MgMn alloys, J. Manuf. Process., 56(2020), p. 500.Article Google Scholar 
  13. C.S. Ma, W.B. Yu, T.T. Zhang, Z.H. Zhang, Y.H. Ma, and S.M. Xiong, The effect of slow shot speed and casting pressure on the 3D microstructure of high pressure die casting AE44 magnesium alloy, J. Magnes. Alloys, 11(2023), No. 2, p. 753.Article CAS Google Scholar 
  14. Z.D. Li, N. Limodin, A. Tandjaoui, P. Quaegebeur, P. Osmond, and D. Balloy, Influence of Sr, Fe and Mn content and casting process on the microstructures and mechanical properties of AlSi7Cu3 alloy, Mater. Sci. Eng. A, 689(2017), p. 286.Article CAS Google Scholar 
  15. L.F. Zhang, J.W. Gao, L.N.W. Damoah, and D.G. Robertson, Removal of iron from aluminum: A review, Miner. Process. Extr. Metall. Rev., 33(2012), No. 2, p. 99.Article Google Scholar 
  16. S.X. Ji, W.C. Yang, F. Gao, D. Watson, and Z.Y. Fan, Effect of iron on the microstructure and mechanical property of Al–Mg–Si–Mn and Al–Mg–Si diecast alloys, Mater. Sci. Eng. A, 564(2013), p. 130.Article CAS Google Scholar 
  17. W.C. Yang, F. Gao, and S.X. Ji, Formation and sedimentation of Fe-rich intermetallics in Al–Si–Cu–Fe alloy, Trans. Nonferrous Met. Soc. China, 25(2015), No. 5, p. 1704.Article CAS Google Scholar 
  18. T. Xiao, G.Q. Lv, Y. Bao, W.C. Duo, L. Xu, and W.H. Ma, Electromagnetic separation of coarse Al–Si melts: The migration behavior of iron-rich phase and continuous growth of primary silicon, J. Alloys Compd., 819(2020), art. No. 153006.
  19. M. Timpel, N. Wanderka, R. Schlesiger, et al., The role of strontium in modifying aluminium–silicon alloys, Acta Mater., 60(2012), No. 9, p. 3920.Article CAS Google Scholar 
  20. H.Q. Duan, Z.Y. Han, and B. Wang, Research progress on non-heat treatment die-casting aluminum alloy for automotive structural parts, Autom. Technol. Mater., (2022), No. 5, p. 1.
  21. X.Y. Jiao, Y.F. Zhang, J. Wang, et al., Characterization of externally solidified crystals in a high-pressure die-cast AlSi10MnMg alloy and their effect on porosities and mechanical properties, J. Mater. Process. Technol., 298(2021), art. No. 117299.
  22. W.B. Yu, C.S. Ma, Y.H. Ma, and S.M. Xiong, Correlation of 3D defect-band morphologies and mechanical properties in high pressure die casting magnesium alloy, J. Mater. Process. Technol., 288(2021), art. No. 116853.
  23. K.G. Basavakumar, P.G. Mukunda, and M. Chakraborty, Influence of grain refinement and modification on microstructure and mechanical properties of Al–7Si and Al–7Si–2.5Cu cast alloys, Mater. Charact., 59(2008), No. 3, p. 283.Article CAS Google Scholar 
  24. F. Wang, D. Qiu, Z.L. Liu, J. Taylor, M. Easton, and M.X. Zhang, Crystallographic study of Al3Zr and Al3Nb as grain refiners for Al alloys, Trans. Nonferrous Met. Soc. China, 24(2014), No. 7, p. 2034.Article CAS Google Scholar 
  25. Z.N. Chen, H.J. Kang, G.H. Fan, et al., Grain refinement of hypoeutectic Al–Si alloys with B, Acta Mater., 120(2016), p. 168.Article CAS Google Scholar 
  26. J.H. Ding, C. Lu, Y.J. Sun, C.X. Cui, and E.T. Zhao, Refining and modification effects of (Al, Zr, Si)–Al4Sr on Al–7Si–0.5Mg alloy, J. Mater. Res. Technol., 15(2021), p. 1604.
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Tags: aluminum alloy; ,Aluminum Casting; ,Die casting; ,High pressure die casting; ,High pressure die casting (HPDC); ,Mechanical Property; ,Microstructure; ,Review; ,자동차; ,자동차 산업