Microstructural refinement and tensile properties enhancement of the Mg-9Al-1Zn alloy after hot extrusion

Afsharnaderi, Aria; Lotfpour, Mehrab; Malekan, Mehdi; Emamy, Massud

doi:10.22059/jufgnsm.2020.02.09

Microstructural refinement and tensile properties enhancement of the Mg-9Al-1Zn alloy after hot extrusion

Document Type : Research Paper

Authors

School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran.

10.22059/jufgnsm.2020.02.09

Abstract

The impact of hot extrusion process on the grain refinement and tensile properties for the rare earth elements (RE) and strontium (Sr)-containing Mg-9Al-1Zn alloys was studied. Based on the microstructural analysis, the grain size values reduced after the hot extrusion process, compared to the cast alloys. Moreover, the tensile properties of the extruded alloys were remarkably higher than the cast alloys. These extraordinary results were related to the grain refinement by the dynamic recrystallization phenomenon, and fragmentation and distribution of the intermetallics. Moreover, the RE/Sr additions improved the grain size reduction, owing to the presence of fragmented Al₁₁RE₃ intermetallics.

Keywords

References

1. Polmear IJ. Magnesium alloys and applications. Materials Science and Technology. 1994;10(1):1-16.

2. Pan F, Yang M, Chen X. A Review on Casting Magnesium Alloys: Modification of Commercial Alloys and Development of New Alloys. Journal of Materials Science & Technology. 2016;32(12):1211-21.

3. Mordike BL, Ebert T. Magnesium. Materials Science and Engineering: A. 2001;302(1):37-45.

4. Kim JM, Park BK, Shin KS, Jun JH, Kim KT, Jung WJ. Development of Mg-Al-Zn Based Diecasting Alloys for Elevated Temperature Applications. Materials Science Forum. 2005;475-479:525-8.

5. Zhang D, Zhang D, Bu F, Li X, Guan K, Yang Q, et al. Effects of minor Sr addition on the microstructure, mechanical properties and creep behavior of high pressure die casting AZ91-0.5RE based alloy. Materials Science and Engineering: A. 2017;693:51-9.

6. Jia R, Yu S, Li D, Zhang T, Wang F, Zhong C. Study on the effect of mischmetal (La,Ce) on the micro-galvanic corrosion of AZ91 alloy using multiscale methods. Journal of Alloys and Compounds. 2019;778:427-38.

7. Zha M, Zhang H-M, Wang C, Wang H-Y, Zhang E-B, Jiang Q-C. Prominent role of a high volume fraction of Mg17Al12 particles on tensile behaviors of rolled Mg–Al–Zn alloys. Journal of Alloys and Compounds. 2017;728:682-93.

8. Che C, Cai Z, Yang X, Cheng L, Du Y. The effect of co-addition of Si, Ca and RE on microstructure and tensile properties of as-extruded AZ91 alloy. Materials Science and Engineering: A. 2017;705:282-90.

9. Bu F, Yang Q, Guan K, Qiu X, Zhang D, Sun W, et al. Study on the mutual effect of La and Gd on microstructure and mechanical properties of Mg-Al-Zn extruded alloy. Journal of Alloys and Compounds. 2016;688:1241-50.

10. Li R, Pan F, Jiang B, Dong H, Yang Q. Effect of Li addition on the mechanical behavior and texture of the as-extruded AZ31 magnesium alloy. Materials Science and Engineering: A. 2013;562:33-8.

11. Wu RZ, Yan YD, Wang GX, Murr LE, Han W, Zhang ZW, Zhang ML. Recent progress in magnesium–lithium alloys. International Materials Reviews. 2015 Feb 1;60(2):65-100.

12. Srinivasan A, Pillai UTS, Pai BC. Effect of Pb addition on ageing behavior of AZ91 magnesium alloy. Materials Science and Engineering: A. 2007;452-453:87-92.

13. Wan D-q, Hu Y-l, Ye S-t, Wang H-b, Wei S-m. Effects of Pb on microstructure, mechanical properties and corrosion resistance of as-cast Mg97Zn1Y2 alloys. China Foundry. 2018;15(6):443-8.

14. Zhao HL, Guan SK, Zheng FY. Effects of Sr and B addition on microstructure and mechanical properties of AZ91 magnesium alloy. Journal of Materials Research. 2007;22(9):2423-8.

15. Suresh M, Srinivasan A, Ravi KR, Pillai UTS, Pai BC. Influence of boron addition on the grain refinement and mechanical properties of AZ91 Mg alloy. Materials Science and Engineering: A. 2009;525(1-2):207-10.

16. Guangyin Y, Yangshan S, Wenjiang D. Effects of bismuth and antimony additions on the microstructure and mechanical properties of AZ91 magnesium alloy. Materials Science and Engineering: A. 2001;308(1-2):38-44.

17. Afsharnaderi A, Malekan M, Emamy M, Rasizadeh Ghani J, Lotfpour M. Microstructure Evolution and Mechanical Properties of the AZ91 Magnesium Alloy with Sr and Ti Additions in the As-Cast and As-Aged Conditions. Journal of Materials Engineering and Performance. 2019;28(11):6853-63.

18. Afsharnaderi A, Lotfpour M, Mirzadeh H, Emamy M, Malekan M. Enhanced mechanical properties of as-cast AZ91 magnesium alloy by combined RE-Sr addition and hot extrusion. Materials Science and Engineering: A. 2020;792:139817.

19. Jia R, Yu S, Li D, Zhang T, Wang F, Zhong C. Study on the effect of mischmetal (La, Ce) on the micro-galvanic corrosion of AZ91 alloy using multiscale methods. Journal of Alloys and Compounds. 2019 Mar 25;778:427-38.

20. Chaubey AK, Scudino S, Prashanth KG, Eckert J. Microstructure and mechanical properties of Mg–Al-based alloy modified with cerium. Materials Science and Engineering: A. 2015;625:46-9.

21. Stanford N, Barnett MR. The origin of “rare earth” texture development in extruded Mg-based alloys and its effect on tensile ductility. Materials Science and Engineering: A. 2008;496(1-2):399-408.

22. Fu L, Wang XB, Gou PL, Le QC, Jia WT, Tang Y. Microstructures and Tensile Properties of AZ91 Magnesium Alloys with Ca, Sm, and La Elements Additions. Advanced Engineering Materials. 2017;19(12):1700230.

23. Zhang JB, Tong LB, Xu C, Jiang ZH, Cheng LR, Kamado S, et al. Influence of Ca-Ce/La synergistic alloying on the microstructure and mechanical properties of extruded Mg–Zn alloy. Materials Science and Engineering: A. 2017;708:11-20.

24. You S, Huang Y, Kainer KU, Hort N. Recent research and developments on wrought magnesium alloys. Journal of Magnesium and Alloys. 2017;5(3):239-53.

25. Chen L, Liang M, Zhao G, Zhou J, Zhang C. Microstructure evolution of AZ91 alloy during hot extrusion process with various ram velocity. Vacuum. 2018;150:136-43.

26. Bamberger M. Structural refinement of cast magnesium alloys. Materials Science and Technology. 2001;17(1):15-24.

27. Robson JD, Henry DT, Davis B. Particle effects on recrystallization in magnesium–manganese alloys: Particle-stimulated nucleation. Acta Materialia. 2009;57(9):2739-47.

28. Xu SW, Kamado S, Honma T. Effect of homogenization on microstructures and mechanical properties of hot compressed Mg–9Al–1Zn alloy. Materials Science and Engineering: A. 2011;528(6):2385-93.

29. ASM Handbook, ume 4, ASM International, Metals Park, Ohio, 1991.

30. H. Chandler, Heat Treater’s Guide Practices and Procedures for Nonferrous Alloys, third ed., The Materials Information Society, ASM International, 2006.

31. Liu H, Chen Y, Tang Y, Wei S, Niu G. The microstructure, tensile properties, and creep behavior of as-cast Mg–(1–10)%Sn alloys. Journal of Alloys and Compounds. 2007;440(1-2):122-6.

32. Lotfpour M, Emamy M, Dehghanian C, Tavighi K. Influence of Cu Addition on the Structure, Mechanical and Corrosion Properties of Cast Mg-2%Zn Alloy. Journal of Materials Engineering and Performance. 2017;26(5):2136-50.

33. Hirai K, Somekawa H, Takigawa Y, Higashi K. Effects of Ca and Sr addition on mechanical properties of a cast AZ91 magnesium alloy at room and elevated temperature. Materials Science and Engineering: A. 2005;403(1-2):276-80.

34. Zhou J-x, Wang J, Wang J, Yang Y-s. Effects of RE and Sr additions on dendrite growth and phase precipitation in AZ91D magnesium alloy. Transactions of Nonferrous Metals Society of China. 2010;20:s331-s5.

35. Liu SF, Li B, Wang XH, Su W, Han H. Refinement effect of cerium, calcium and strontium in AZ91 magnesium alloy. Journal of Materials Processing Technology. 2009;209(8):3999-4004.

36. Maltais A, Dubé D, Fiset M, Laroche G, Turgeon S. Improvements in the metallography of as-cast AZ91 alloy. Materials Characterization. 2004;52(2):103-19.

37. Mirzadeh H. Constitutive analysis of Mg–Al–Zn magnesium alloys during hot deformation. Mechanics of Materials. 2014;77:80-5.

38. Pourbahari B, Mirzadeh H, Emamy M. Toward unraveling the effects of intermetallic compounds on the microstructure and mechanical properties of Mg–Gd–Al–Zn magnesium alloys in the as-cast, homogenized, and extruded conditions. Materials Science and Engineering: A. 2017;680:39-46.

39. Robson JD, Henry DT, Davis B. Particle effects on recrystallization in magnesium–manganese alloys: Particle-stimulated nucleation. Acta Materialia. 2009 May 1;57(9):2739-47.

40. Imandoust A, Barrett CD, Al-Samman T, Inal KA, El Kadiri H. A review on the effect of rare-earth elements on texture evolution during processing of magnesium alloys. Journal of Materials Science. 2017;52(1):1-29.

41. Pourbahari B, Mirzadeh H, Emamy M, Roumina R. Enhanced Ductility of a Fine-Grained Mg-Gd-Al-Zn Magnesium Alloy by Hot Extrusion. Advanced Engineering Materials. 2018;20(8):1701171.

42. Zamani R, Mirzadeh H, Emamy M. Mechanical properties of a hot deformed Al-Mg2Si in-situ composite. Materials Science and Engineering: A. 2018;726:10-7.