Effects of Solution Atoms and Precipitates on Isochronal Annealing Behavior of Cold-Rolled Squeeze-Cast SiCw/Al Composites

Wenglong Zhang, Mingyuan Gu
DOI: 10.4236/msa.2011.25062                

Abstract

SiCw/Al and SiCw/6061Al composites, which contained 15 vol pct of whiskers, were fabricated through a squeeze cast route followed by cold rolling and isochronal annealing. Effects of whicker, solution atoms and precipitates on isochronal annealing behavior of cold rolled composites were investigated by comparing the isochronal annealing behavior between pure Al, SiCw/Al, solution-treated SiCw/6061Al and aged SiCw/6061Al. It was found that the recrystallization of SiCw/Al composite occurs earlier than that of pure Al, indicating SiCw has a role of particle stimulated nucleation. Solution atoms have no significant influence on the isochronal annealing behavior of SiCw/6061Al composite, while precipitates have such a strong retarding effect on the recrystallization of SiCw/6061Al composite that the isochronal annealing curve of aged SiCw/6061 composite loses the definable recrystallization step.

Keywords

Composite Materials, Deformation and Fracture, Isochronal Annealing, Precipitates

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	K. Suganuma and T. Fujita, “Hot Extrusion of AA7178 Reinforced with Alumina Short Fibre,” Materials Science and Technology, Vol. 5, No. 8, August 1989, pp. 249-254.
[2]	M. Lieblich and G. J. Gonzalez-Doncel, “Extrudability of PM 2124/SiCp Aluminium Matrix Composite,” Materials Letters, Vol. 16, No. 1, January 1997, pp. 726-728.
[3]	W. Zhang and D. Wang, “Forming Process of Hot-Extruded SiCw/6061Al Composites,” Transactions of Nonferrous Metals Society of China, Vol. 8, No. 3, Mach 1998, pp. 432-436.
[4]	F. J. Humphreys and W. S. Miller, “A Network Model for Recovery and Recrystallization,” Materials Science and Technology, Vol. 6, No. 1, January 1990, pp. 1157-1166.
[5]	R. D. Doherty, D. A. Hughes and F. J. Humphreys, “Current Issues in Recrystallisation: A Review,” Materials Science and Engineering A, Vol. 238, No. 2, February 1997, pp. 219-274. doi:10.1016/S0921-5093(97)00424-3
[6]	R. Nagarajan and I. Dutta, “A Novel Approach for Optimizing the Fracture Toughness of Precipitation-Hardenable Al-SiCp Composites,” Metallurgical and Materials Transactions A, Vol. 32A, No. 2, February 2001, pp. 433-436. doi:10.1007/s11661-001-0276-6
[7]	N. Yazdian, F. Karimzadeh and M. Tavoosi, “Microstructural Evolution of Nanostructure 7075 Aluminum Alloy during Isothermal Annealing,” Journal of Alloy and Compounds, Vol. 493, No. 1-2, February 2010, pp. 137-141. doi:10.1016/j.jallcom.2009.12.144
[8]	W. B. Du, K. Tatsuzawa and T. Aizawa, “Forming and Microstructure Control of Ceramic/Metal Composite Wires,” Materials Letters, Vol. 54, No. 2-3, May 2002, pp. 145-151. doi:10.1016/S0167-577X(01)00553-5
[9]	B. Sustarsic, M. Dobersek and B. Breskvar, “Properties of Hot Extruded Al Sic Metal Matrix Composites,” Metalurgija, Vol. 38, No. 3, July 1999, pp. 143-149.
[10]	H. Xu and E. J. Palmiere, “Particulate Refinement and Redistribution during the Axisymmetric Compression of an Al/SiCp Metal Matrix Composite,” Composites A, Vol. 30, No. 3, March 1999, pp. 203-211. doi:10.1016/S1359-835X(98)00169-9
[11]	Y. L. Liu and N. Hansen, “Recrystallisation Microstructure in Cold-Rolled Aluminium Composites Reinforced by Silicon Carbide Whiskers,” Metallurgical and Materials Transactions A, Vol. 20A, No. 2, February 1989, pp. 1743-1753. doi:10.1007/BF02663206
[12]	D. J. Jensen and N. Hansen, “Effect of Recrystallization Temperature on Texture and Grain Size of Al-SiC Composites,” Materials Science and Technology, Vol. 7, No. 9, September 1991, pp. 369-375.
[13]	Y. L. Liu and D. J. Jensen, “Hardening Behaviour of Metal Matrix Composites Coupled to Numerical Predictions,” Strength of Materials, Vol. 23A, No. 2, February 1994, pp. 381-384.
[14]	Y. L. Liu and N. Hansen, “Effect of Dispersion Parameters and Cold Deformation on Recrystallization in of Al-SiC Composites,” Materials Science and Technology. Vol. 7, No. 6, June 1991, pp. 270-275.
[15]	D. Yu and P. R. Munroe, “Recrystallization in Sic Particulate-Reinforced 6061-Aluminum Metal-Matrix Composites Following Low Strain Deformation,” Scripta Metallurgical and Materials, Vol. 30, No. 7, July 1994, pp. 927-932. doi:10.1016/0956-716X(94)90417-0
[16]	R. Manna and J. J. Sarkar, “Effect of Second Phase Precipitation on Recovery and Recrystallization Behaviour of Cold-Worked Al 2024-SiCp Composites,” Journal of Materials Science, Vol. 31, No. 2, February 1996, pp. 1625-1631. doi:10.1007/BF00357874
[17]	R. A. Shahani and T. W. Clyne, “Recrystallization in Fibrous and Particulate Metal Matrix Composites,” Materials Science and Engineering A, Vol. 4, No. 2, February 1994, pp. 281-285.
[18]	D. Yu and P. R. Munroe, “Microstructural Evolution of a Cold-Deformed 6061Al Reinforced with SiC Particles during Subsequent Annealing,” Journal of Materials Science, Vol. 31, No. 3, February 1996, pp. 625-631. doi:10.1007/BF00367878
[19]	J. M. Root, D. P. Field and T. W. Nelson, “Crystallographic Texture in the Friction-Stir-Welded Metal Matrix Composite Al6061 with 10 Vol Pct Al2O3,” Metallurgical and Materials Transactions A, Vol. 40A, No. 9, September 2009, pp. 2109-2114. doi:10.1007/s11661-009-9883-4
[20]	L. Ceschini, G. Minak and A. Morri, “Forging of the AA6061/23 vol%Al2O3p Composite: Effects on Microstructure and Tensile Properties,” Materials Science and Engineering A, Vol. 513-514, No. 5, May 2009, pp. 176-184. doi:10.1016/j.msea.2009.01.057
[21]	F. J. Humphreys, “Recrystallization Mechanisms in Two- Phase Alloys,” Materials. Science, Vol. 13, No. 5, May 1979, pp. 136-145.
[22]	P. Cotterill and P. R. Mould, “Recrystallization and Grain Growth in Metals,” Surrey University Press, Guildford, 1976.