Effect of Homogenizing Treatment on Microstructure and Property of Al-Zn-Mg-Cu-Zr Aluminum Alloy

Abstract:

A series of Al-6.3Zn-2.3Mg-2.3Cu-0.15Zr alloys with different reduce of Zn, Mg, Cu and Zr were prepared by ingot-metallurgy processing. Effects of homogenization on the microstructure and properties of Al-Zn-Mg-Cu-Zr aluminium alloy were respectively studied by means of metallographic microscopy, electrical conductivity test, differential thermal analysis and X-ray diffraction phase analysis. The results indicated that the overheating temperature of these alloys is between 473°C and 477°C, and there was little difference to the overheating temperature of 7050 alloy. During homogenization process, using three kinds of developed heat treatment of homogenization of 7050 alloy, with the rising of homogenization temperature and the complication of the homogenization heat treatment, the electrical conductivity decreased and hardness gradually increased. The three-step homogenization has a better effect than single homogenization, as it can completely eliminate the endothermic peak of non-equilibrium phases. Many MgZn₂ phases are present in the ingot with three-step homogenization and slow cooling.

• Periodical: Materials Science Forum (Volume 877)
• Pages: 587-592
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.877.587
• Online since: November 2016
• Authors: Gao Song Wang*, Qing Qiang Chen, Kai Tao, Qi Chao Chen, Zhi Hao Zhao
• Keywords: Al-Zn-Mg-Cu-Zr Alloy, Homogenization, Microstructure, Property

References

[1] Hirsch J., Bassan D., Lahaye C., Goede M., Aluminum in Innovative Light-weight Car Design[J], Materials Transactions, 2011, 55: 818-824.

[2] Kleiner M., Geiger M., Klaus A., Manufacturing of Lightweight Component by Metal Forming[J], CIRP Annals-Manufacturing Technology, 2003, 52, 521-542.

DOI: 10.1016/s0007-8506(07)60202-9

[3] Liu C., Northwood D.O., Bhole S.D., Tensile Fracture Behaviour in CO2 Laser Beam Welds of 7075-T6 Aluminum Alloy[J], Materials and Design, 2004, 25: 573-577.

DOI: 10.1016/j.matdes.2004.02.017

[4] Sotirov N., Simon P., Chimani Ch., Uffelmann D., Melzer C., Warm Deep Drawability of Peak-Aged 7075 Aluminum Sheet Alloy[J], Key Engineering Materials, 2012, 504-506: 955-960.

DOI: 10.4028/www.scientific.net/kem.504-506.955

[5] Joseph H M, Hyman R. Influence of nonequilibrium second-phase particles formed during solidification upon the mechanical behavior of an aluminum alloy[J]. Metall. Trans., 1971, 2(2): 427-435.

DOI: 10.1007/bf02663329

[6] Yu Zeng. Study on Microstructure and Properties of ultra-high strength AI-Zn-Mg-Cu-Zr alloy [D]. Chang Sha: Central South University , (2004).

[7] DorWard R.C., Beernsen D.J. Grain structure and quench-rate effects on strength and toughnessofAA7050 Al-Zn-Mg-Cu-Zr alloy plate [J]. Metall. Trans. A, 1995, 26(9): 2481.

DOI: 10.1007/bf02671263

[8] Choudhery M.A., Ashraf M. Effect of heat treatment and stress relaxation in 7075 aluminum alloy[J]. Journal of alloys and compounds, 2007, 437: 113-116.

DOI: 10.1016/j.jallcom.2006.07.079

[9] Wang C, Zhou J, Yang ZF, et al. Change of the microstructure of 7050 aluminum alloy ingot during homogenization annealing [J]. Light Alloy Fabrication Technology, 2007, 35: 23-24.

[10] Robson JD. Microstructural evolution in aluminum alloy 7050 during processing[J]. Materials Science and Engineering, 2004 A382: 112-121.

DOI: 10.1016/j.msea.2004.05.006

[11] Fan XG, Jiang DM, Meng QC, et al. Characterization of precipitation microstructure and properties of 7150 aluminum alloy[J]. Materials Science and Engineering, 2006 A427: 130-135.

DOI: 10.1016/j.msea.2006.04.043

[12] Lu Z, Yang SJ, Jiang HF, et al. A study of homogenization processes for a new type ultra-high strength aluminum alloy [J]. Journal of Aeronautical Materials, 2001（2）：14-17.

[13] Tian Y. The physical properties of alloy [M], Bei Jing：Aviation Industrial Publishing House, 1994, 4: 59-60.

[14] Fang JX, Chen D. Solid State Physics [M], Bei Jing：Higher Education Press, 1981, 7: 211.