Tensile Properties and Microstructure of Joined Vacuum Die Cast Aluminum Alloy A356 (T6) and Wrought Alloy 6061

Abstract:

In the present work, fusion-joining of vacuum high pressure die cast (HPDC) aluminum alloy A356 and wrought alloy 6061 by applying Gas Metal Arc Welding (GMAW-MIG) process was investigated to understand the effect of the MIG process on the microstructure and tensile behaviors of the base joined alloys (T6 Heat treatment A356 and 6061). The microstructures of the base metal (T6 heat treatment A356 and 6061), Heat Affected Zone (HAZ) and Fusion Zone (filler metal ER4043) were analyzed by Scanning Electron Microscopy (SEM) and optical microscopy. The results of tensile testing indicated that, the ultimate tensile strength (UTS) and yield strength (YS) of V-HPDC alluminium A356 subjected to T6 thermal treatment were relatively low, compared to both wrought alloy 6061 and the filler metal (ER 4043). The microstructure analysis showed that the low strengths of T6 A356 alloy should be at least attributed to the absence of the magnesium-based intermetallic phase, coarse grain structure and the presence of porosity, which resulted from the HPDC process, MIG welding and thermal treatment.

• Periodical: Advanced Materials Research (Volume 939)
• Pages: 90-97
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.939.90
• Online since: May 2014
• Authors: Meng Wang*, Yan Da Zou, Henry Hu, Gary Meng, Patrick Cheng, Yeou Li Chu
• Keywords: A356 Aluminum Alloy, AA6061 Aluminum Alloy, Gas Metal Arc Welding (GMAW-MIG), Tensile Properties, Vacuum High Pressure Die Cast (V-HPDC)

References

[1] P. Krajewski, A. Sachdev, A. Luo, J. Carsley, J. Scroth, Automotive aluminum and magnesium: innovation and opportunities, Light Metals Age, 4 (2009) 6-13.

[2] L. Sulley, Die Casting, Metals Handbook-Casting, nineth ed., ASM International, Materials Park, Ohio, (1988).

[3] H. Kaufmann and P.J. Uggowitzer, Metallurgy and processing of high-integrity kight metal pressure castings, Schiele&Schon, Berlin, (2007).

[4] X.P. Niu, B.H. Hu, I. Pinwill, H. Li, Vacuum assisted high pressure die casting of aluminum alloys, Journal of Materials Processing Technology, 105 (2000) 119-127.

DOI: 10.1016/s0924-0136(00)00545-8

[5] X. Zhang, K. Ahmmed, M. Wang, H. Hu, Influence of aging temperatures and times on mechanical properties of vacuum high pressure die cast aluminum alloy A356, Advanced Materials Research, 445 (2012) 277-282.

DOI: 10.4028/scientific5/amr.445.277

[6] Z.Y. Ma, S. R. Sharma, R.S. Mishra, M.W. Mahoney, Microstructural modification of cast aluminum alloys via friction stir processing, Materials Science Forum, 426 (2003) 2891-2896.

DOI: 10.4028/www.scientific.net/msf.426-432.2891

[7] Y.G. Kim, H. Fujii, T. Tsumura, T. Komazaki, K. Nakata, Three defect types in friction stir welding of aluminum die casting alloy, Materials Science and Engineering A, 145 (2006) 250-254.

DOI: 10.1016/j.msea.2005.09.072

[8] L. Hwang, C. Gung, T. S. Shih, A study on the qualities of GTA-welded squeeze-cast A356 alloy, Journal of Materials Processing Technology, 116 (2001) 101-113.

DOI: 10.1016/s0924-0136(01)00829-9

[9] D. Lindsey, J. Wallace, Effect of vent size and design, lubrication practice, metal degassing, die texturing and filling of shot sleeve on die casting soundness, Proceedings of 7th International Die Casting Congress, (1972) 1–15.