Abstract
Microstructural evolution of semi-solid 7075 Al alloy manufactured by strain-induced melt activation (SIMA) process was investigated. The effects of different processing parameters, such as isothermal temperature and holding time on the semi-solid microstructures (the liquid volume fraction, average grain size, and degree of spheroidization of the solid particles) during partial remelting have been investigated on 7075 Al alloy that was extruded by an extrusion ratio of 20 before remelting. Experiments of remelting were carried out in the range of 560-610 °C for 10, 20, and 30 min holding time and then the specimens were quenched in cold water. Microstructure of quenched samples were observed under optical microscope and then analyzed via image analysis. The results showed that high semi-solid isothermal temperature would increase the liquid volume fraction and accelerate the spherical processing of the solid particles. Furthermore at long holding time, the globular grains coarsened slightly and the average grains size are increased. The experimental results showed that the optimum process parameters, should be chosen at isothermal temperature of 580 °C with the holding time, <30 min.
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References
H.V. Atkinson, Modeling the Semisolid Processing of Metallic Alloys, Prog. Mater. Sci., 2005, 50, p 341–412
Z. Fan, Semisolid Metal Processing, Int. Mater. Rev., 2002, 47, p 67
S. Chayong, H.V. Atkinson, and P. Kapranos, Thixoforming 7075 Aluminum Alloys, Mater. Sci. Eng. A, 2005, 390, p 3–12
J. Dong, J.Z. Cui, Q.C. Le, and G.M. Lu, Liquidus Semi-Continuous Casting, Reheating and Thixoforming of a Wrought Aluminum Alloy 7075, Mater. Sci. Eng., 2003, A345, p 234–242
L. Sang-Yong, L. Jung-Hwan, and L. Young-Seon, Characterization of Al 7075 Alloys After Cold Working and Heating in the Semi-Solid Temperature Range, Mater. Process Technol., 2001, 111, p 42–47
L. Zhang, Y.B. Liu, Z.Y. Cao, Y.F. Zhang, and Q.Q. Zhang, Effects of Isothermal Process Parameters on the Microstructure of Semisolid AZ91D Alloy Produced by SIMA, Mater. Process Technol., 2009, 209, p 792–797
N. Saklakoglu, I. Etem Saklakoglu, M. Tanoglu, O. Oztas, and O. Cubukcuoglu, Mechanical Properties and Microstructural Evaluation of AA5013 Aluminum Alloy Treated in the Semi-Solid State by SIMA Process, Mater. Process Technol., 2004, 148, p 103–107
Y. Lu, M. Li, Y. Niu, and X. Li, Microstructure and Element Distribution During Partial Remelting of an Al-4Cu-Mg Alloy, Mater. Eng. Perform., 2008, 17(1), p 25–29
S.-c. Wang, Y.-y. Li, W.-p. Chen, and X.-p. Zheng, Microstructure Evolution of Semi-Solid 2024 Alloy During Two-Step Reheating Process, Trans. Nonferrous Met. Soc. China, 2008, 18, p 784–788
H.-m. Guo, X.-j. Yang, and M. Zhang, Microstructure Characteristics and Mechanical Properties of Rheoformed Wrought Aluminum Alloy 2024, Trans. Nonferrous Met. Soc. China, 2008, 18, p 555–561
J.G. Wang, H.Q. Lin, H.Y. Wang, and Q.C. Jiang, Effects of Different Processing Parameters on the Semisolid Microstructure of the AZ91D Alloy During Partial Remelting, J. Alloys Compd., 2008, 466, p 98–105
J. Jiang, Y. Wang, J. Qu, Z. Du, Y. Sun, and S. Luo, Microstructure Evolution of AM60 Magnesium Alloy Semisolid Slurry Prepared by New SIMA, J. Alloys Compd., 2010, 497, p 62–67
H.V. Atkinson, K. Burke, and G. Vaneetveld, Recrystallisation in the Semi-Solid State in 7075 Aluminium Alloy, Mater. Sci. Eng., 2008, 490, p 266–276
Q.Q. Zhang, Z.Y. Cao, Y.F. Zhang, G.H. Su, and Y.B. Liu, Effects of Compression Ratio on the Microstructure Evolution of Semisolid AZ91D Alloy, Mater. Process. Technol., 2007, 184, p 195–200
G. Hirt and R. Kopp, Thixoforming: Semi-Solid Metal Processing, Wiley Publication, New York, 2009
D. Liu, H.V. Atkinson, and H. Jones, Thermodynamic Prediction of Thixoformability in Alloys Based on the Al-Si-Cu and Al-Si-Cu-Mg Systems, Acta Mater., 2005, 53, p 3807–3819
E. Tzimas and A. Zavaliangos, Evolution of Near-Equiaxed Microstructure in the Semisolid State, Mater. Sci. Eng. A, 2000, 289, p 228–240
W. Lapkowski, Some Studies Regarding Thixoforming of Metal Alloys, Mater. Sci. Technol., 1998, 80–81, p 463–468
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Mohammadi, H., Ketabchi, M. & Kalaki, A. Microstructure Evolution of Semi-Solid 7075 Aluminum Alloy During Reheating Process. J. of Materi Eng and Perform 20, 1256–1263 (2011). https://doi.org/10.1007/s11665-010-9762-6
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DOI: https://doi.org/10.1007/s11665-010-9762-6