Microstructure and mechanical properties of a cast heat-resistant rare-earth magnesium alloy
Tóm tắt
Microstructure, mechanical properties and phase transformation of a heat-resistant rare-earth (RE) Mg-16.1Gd-3.5Nd-0.38Zn-0.26Zr-0.15Y (wt.%) alloy were investigated. The as-cast alloy is composed of equiaxed α-Mg matrix, net-shaped Mg5RE and Zr-rich phases. According to aging hardening curves and tensile properties variation, the optimized condition of solution treatment at 520 °C for 8 h and subsequent aging at 204 °C for 12 h was selected. The continuous secondary Mg5RE phase predominantly formed at grain boundaries during solidification transforms to residual discontinuous β-Mg5RE phase and fine cuboid REH2 particles after heat treatment. The annealed alloy exhibits good comprehensive tensile property at 350 °C, with ultimate tensile strength of 153 MPa and elongation to fracture of 6.9%. Segregation of RE elements and eventually RE-rich precipitation at grain boundaries are responsible for the high strength at elevated temperature.
Tài liệu tham khảo
Kim Y J, Kim S H, Lee J U, et al. Effects of cold pre-forging on microstructure and tensile properties of extruded AZ80 alloy. Materials Science and Engineering: A, 2017, 708: 405–410.
Cai Z, Chen F, Guo J. Constitutive model for elevated temperature flow stress of AZ41M magnesium alloy considering the compensation of strain. Journal of Alloys and Compounds, 2015, 648: 215–222.
Mordike B L, Ebert T. Magnesium: Properties-applications-potential. Materials Science and Engineering: A, 2001, 302(1): 37–45.
Kaiser M S, Datta S, Roychowdhury A, et al. Age hardening behavior of wrought Al-Mg-Sc alloy. Materials and Manufacturing Processes, 2007, 23(1): 74–81.
Li J, Chen R, Ma Y, et al. Characterization and prediction of microporosity defect in sand cast WE54 alloy castings. Materials Science & Technology, 2014, 30(10): 991–997.
Wang J, Meng J, Zhang D, et al. Effect of Y for enhanced age hardening response and mechanical properties of Mg-Gd-Y-Zr alloys. Materials Science and Engineering: A, 2007, 456(1): 78–84.
Yang Y, Yang M, He C, et al. Rare earth improves strength and creep resistance of additively manufactured Zn implants. Composites, Part B: Engineering, 2021, 216: 108882.
Masoudpanah S M, Mahmudi R. Effects of rare-earth elements and Ca additions on the microstructure and mechanical properties of AZ31 magnesium alloy processed by ECAP. Materials Science and Engineering: A, 2009, 526(1): 22–30.
Zhou H, Cheng G M, Ma X L, et al. Effect of Ag on interfacial segregation in Mg-Gd-Y-(Ag)-Zr alloy. Acta Materialia, 2015, 95: 20–29.
Garces G, Máthis K, Barea R, et al. Effect of precipitation in the compressive behavior of high strength Mg-Gd-Y-Zn extruded alloy. Materials Science and Engineering: A, 2019, 768: 138452.
Li Y, Qu C, Wang J, et al. Exceptional aging hardening behaviour of nanocrystalline Mg-Y-Nd-Gd-Zr alloy prepared by high pressure torsion. Journal of Alloys and Compounds, 2020, 813: 152123.
Xu C, Nakata T, Fan G H, et al. Enhancing strength and creep resistance of Mg-Gd-Y-Zn-Zr alloy by substituting Mn for Zr. Journal of Magnesium and Alloys, 2019, 7(3): 388–399.
Liu Q, Ding X, Liu Y, et al. Analysis on micro-structure and mechanical properties of Mg-Gd-Y-Nd-Zr alloy and its reinforcement mechanism. Journal of Alloys and Compounds, 2017, 690: 961–965.
Wu G, Wang C, Sun M, et al. Recent developments and applications on high-performance cast magnesium rare-earth alloys. Journal of Magnesium and Alloys, 2021, 9(1): 1–20.
Jiang R, Qian S, Dong C, et al. Composition optimization of high-strength Mg-Gd-Y-Zr alloys based on the structural unit of Mg-Gd solid solution. Journal of Materials Science & Technology, 2021, 72: 104–113.
Peng Q, Wu Y, Fang D, et al. Microstructures and mechanical properties of Mg-8Gd-0.6Zr-xNd (x=0, 1, 2 and 3 mass%) alloys. Journal of Materials Science, 2007, 42(11): 3908–3913.
Massalski T, Okamoto H, Subramanian P, et al. Binary alloy phase diagrams. ASM International, 1986.
Hagihara K, Kinoshita A, Sugino Y, et al. Effect of long-period stacking ordered phase on mechanical properties of Mg97Zn1Y2 extruded alloy. Acta Materialia, 2010, 58(19): 6282–6293.
Hagihara K, Yokotani N, Umakoshi Y. Plastic deformation behavior of Mg12YZn with 18R long-period stacking ordered structure. Intermetallics, 2010, 18(2): 267–276.
Zhou H, Liu K, Zhang L, et al. Influence of high pressure during solidification on the microstructure and strength of Mg-Zn-Y alloys. Journal of Rare Earths, 2016, 34(4): 435–440.
Ma Q, StJohn D H, Frost M T. Characteristic zirconium-rich coring structures in Mg-Zr alloys. Scripta Materialia, 2002, 46(9): 649–654.
Li J, He Z, Fu P, et al. Heat treatment and mechanical properties of a high-strength cast Mg-Gd-Zn alloy. Materials Science and Engineering: A, 2016, 651: 745–752.
Ozaki T, Kuroki Y, Yamada K, et al. Mechanical properties of newly developed age hardenable Mg-3.2 mol%Gd-0.5 mol%Zn casting alloy. Materials Transactions, 2008, 49(10): 2185–2189.
Zhang Y, Wu Y, Peng L, et al. Microstructure evolution and mechanical properties of an ultra-high strength casting Mg-15.6Gd-1.8Ag-0.4Zr alloy. Journal of Alloys and Compounds, 2014, 615: 703–711.
Zhang J, Leng Z, Liu S, et al. Microstructure and mechanical properties of Mg-Gd-Dy-Zn alloy with long period stacking ordered structure or stacking faults. Journal of Alloys and Compounds, 2011, 509(29): 7717–7722.
Jahedi M, McWilliams B A, Knezevic M. Deformation and fracture mechanisms in WE43 magnesium-rare earth alloy fabricated by direct-chill casting and rolling. Materials Science and Engineering: A, 2018, 726: 194–207.
Hyer H, Zhou L, Benson G, et al. Additive manufacturing of dense WE43 Mg alloy by laser powder bed fusion. Additive Manufacturing, 2020, 33: 101123.
Yin Z, Liu X, Gao N, et al. Grain refinement of a NiCoFe medium entropy alloy: Composition design from solute interaction perspective. Journal of Alloys and Compounds, 2023, 951: 169966.
Wang J, Liu R, Dong X, et al. Microstructure and mechanical properties of Mg-Zn-Y-Nd-Zr alloys. Journal of Rare Earths, 2013, 31(6): 616–621.
Peng Q, Hou X, Wang L, et al. Microstructure and mechanical properties of high performance Mg-Gd based alloys. Materials & Design, 2009, 30(2): 292–296.
Liu X, Zhang Z, Le Q, et al. Effects of Nd/Gd value on the microstructures and mechanical properties of Mg-Gd-Y-Nd-Zr alloys. Journal of Magnesium and Alloys, 2016, 4(3): 214–219.
Yu Z, Xu C, Meng J, et al. Microstructure evolution and mechanical properties of as-extruded Mg-Gd-Y-Zr alloy with Zn and Nd additions. Materials Science and Engineering: A, 2018, 713: 234–243.
Gao Y, Wang Q, Gu J, et al. Behavior of Mg-15Gd-5Y-0.5Zr alloy during solution heat treatment from 500 to 540 °C. Materials Science and Engineering: A, 2007, 459(1): 117–123.
Qian M, Stjohn D H, Frost M T. Characteristic zirconium-rich coring structures in Mg-Zr alloys. Scripta Materialia, 2002, 46(9): 649–654.
Antion C, Donnadieu P, Perrard F, et al. Hardening precipitation in a Mg-4Y-3RE alloy. Acta Materialia, 2003, 51(18): 5335–5348.
Honma T, Ohkubo T, Hono K, et al. Chemistry of nanoscale precipitates in Mg-2.1Gd-0.6Y-0.2Zr (at.%) alloy investigated by the atom probe technique. Materials Science and Engineering: A, 2005, 395(1–2): 301–306.
Jin X, Xu W, Li K, et al. Influence of heat treatment on the evolution of microstructure and mechanical properties of Mg-7Gd-5Y-0.6Zn-0.8Zr magnesium alloy. Materials Science and Engineering: A, 2018, 729: 219–229.
Alizadeh R, Mahmudi R, Ngan A H W, et al. An unusual extrusion texture in Mg-Gd-Y-Zr alloys. Advanced Engineering Materials, 2016, 18(6): 1044–1049.
Yang Z, Wang Z H, Duan H B, et al. Microstructure evolution of Mg-6Gd-2Y alloy during solid solution and aging process. Materials Science and Engineering: A, 2015, 631: 160–165.
Vlček M, Čížek J, Lukáč F, et al. Hydrogen absorption in Mg-Gd alloy. International Journal of Hydrogen Energy, 2017, 42(35): 22598–22604.
Jun J H, Seong K D, Lee M H. Effect of Zirconium on high temperature tensile properties of precipitation-hardened Mg-Nd-Zn casting alloy. International Journal of Modern Physics B, 2009, 23(6): 966–971.
Zheng K, Dong J, Zeng X, et al. Precipitation and its effect on the mechanical properties of a cast Mg-Gd-Nd-Zr alloy. Materials Science and Engineering: A, 2008, 489(1–2): 44–54.
Chen X, Li Q, Zhu L, et al. Abnormal temperature effect on tensile strength of Mg-13Gd-2Y-0.5Zr alloy. Vacuum, 2020, 177: 109398.
Ouyang S, Yang G, Qin H, et al. Effect of the precipitation state on high temperature tensile and creep behaviors of Mg-15Gd alloy. Journal of Magnesium and Alloys, 2022, 10(12): 3459–3469.
Deng Q, Wu Y, Zhu W, et al. Effect of heat treatment on microstructure evolution and mechanical properties of selective laser melted Mg-11Gd-2Zn-0.4Zr alloy. Materials Science and Engineering: A, 2022, 829: 142139.
Czerwinski F, Zielinska-Lipiec A, Pinet P J, et al. Correlating the microstructure and tensile properties of a thixomolded AZ91D magnesium alloy. Acta Materialia, 2001, 49(7): 1225–1235.
Fu J W, Yang Y S. Formation of the solidified microstructure of Mg-Al-Zn alloy under a low-voltage pulsed magnetic field. Journal of Materials Research, 2011, 26(14): 1688–1695.
Fisher D, Kurz W. Fundamentals of solidification. Trans. Tech. Publications, 1998.
Yang M, Guo T, Qin C, et al. Microstructure, tensile and creep properties of as-cast Mg-3.8Zn-2.2Ca-xCe (x=0, 0.5, 1 and 2 wt.%) magnesium alloys. Journal of Rare Earths, 2012, 30(2): 181–188.
Zhang H, Fan J, Zhang L, et al. Effect of heat treatment on microstructure, mechanical properties and fracture behaviors of sand-cast Mg-4Y-3Nd-1Gd-0.2Zn-0.5Zr alloy. Materials Science and Engineering: A, 2016, 677: 411–420.
Huang Y, Yang L, You S, et al. Unexpected formation of hydrides in heavy rare earth containing magnesium alloys. Journal of Magnesium and Alloys, 2016, 4(3): 173–180.
Yamada K, Okubo Y, Shiono M, et al. Alloy development of high toughness Mg-Gd-Y-Zn-Zr alloys. Materials Transactions, 2006, 47(4): 1066–1070.
Anyanwu I A, Kamado S, Kojima Y. Creep properties of Mg-Gd-Y-Zr alloys. Materials Transactions, 2001, 42(7): 1212–1218.
Wang F, Fu B G, Wang Y F, et al. (Y, Gd)H2 phase formation in as-cast Mg-6Gd-3Y-0.5Zr alloy. China Foundry, 2021, 18(3): 217–222.
Stulikova I, Smola B, Buch F V, et al. Development of creep resistant Mg-Gd-Sc alloys with low Sc content. Materials Science & Engineering Technology, 2001, 32(1): 20–24.
Apps P, Karimzadeh H, King J, et al. Phase compositions in magnesium-rare earth alloys containing yttrium, gadolinium or dysprosium. Scripta Materialia, 2003, 48(5): 475–481.
Wang J, Fu J, Dong X, et al. Microstructure and mechanical properties of as-cast Mg-Al-Sn-Y-Nd alloy. Materials & Design, 2012, 36: 432–437.