Effect of PWHT Variables on Microstructure and Mechanical Properties of the Al-Zn Weld Metal
الموضوعات : Journal of Environmental Friendly Materials
M. Forghani
1
(Iranian Institute of Welding and Nondestructive Testing (IWNT), Tehran, Iran)
الکلمات المفتاحية:
ملخص المقالة :
In this investigation the microstructure and mechanical properties of Al-Zn (Al 7075) MIG weld metal were studied in respect to T5 post weld heat treatment variables. Samples were cut from butt weld which were produced by automatic MIG welding with the same heat treatment in different times (10 to 480 minute) and temperatures (85 to 225). The mechanical test results showed that the optimum mechanical properties (as: tensile and yield strength, impact energy and hardness) gained in 155and 120 minute. XRD, Optical metallographic and EDX point analysis results of the sample with best mechanical properties (155 ̊C - 120min) showed that the microstructure consists of fine grain above 15 µm diameter with 15% precipitate, in addition the precipitates were distributed at the grains and grains boundary, at the grains boundary Al2Mg3Zn3 and in the grains CuAl2 were precipitated
[1] J. Norrish, Cambridge England, Chapter 7 (2006), 120.
[2] R.J.Davis, ASM Specialty Handbook, ASM Int, USA, (1993), 236.
[3] S. Kou "Welding Metallurgy" 2nd edition, A. John Wiley and Sons inc. publication, New Jersy, Chapter 15, (2008), 367.
[4] G. Mathers, Woodhead Publishing Limited, Cambridge, England Chapter 2 (2004), 18.
[5] V. Balasubrmanaian, V. Ravixankar, G. Madhusudhan, Mater Sci Eng, A 459(2007)19.
[6]P.K.Ghosh, V.Sharma, J. Mater Trans, 32(1999), 45.
[7] L. K. Berg, V. Hansen, Acta Mater, 49(2001), 3443.
[8] G. D. R. Janaki, T.K.Mitra, V.Shankar, J. Mater Process Technol., 142(2003), 178.
[9] K .Esterling, 2nd edition, Butterworth and Heinemann, Chapter2, Oxford, England, (1992), 69.
[10] H. Sabet, International Conference on Materials Heat Treatment (ICMH 2010), Iran, (2010).
[11] H. Sabet, Welding of Nonferrous Metals, IWNT Publication, Tehran, (2014).
