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Effect of Taper Pin Ratio on Microstructure and Mechanical Property of Friction Stir Welded AZ31 Magnesium Alloy

Authors: N. H. Othman, N. Udin, M. Ishak, L. H. Shah

Abstract:

This study focuses on the effect of pin taper tool ratio on friction stir welding of magnesium alloy AZ31. Two pieces of AZ31 alloy with thickness of 6 mm were friction stir welded by using the conventional milling machine. The shoulder diameter used in this experiment is fixed at 18 mm. The taper pin ratio used are varied at 6:6, 6:5, 6:4, 6:3, 6:2 and 6:1. The rotational speeds that were used in this study were 500 rpm, 1000 rpm and 1500 rpm, respectively. The welding speeds used are 150 mm/min, 200 mm/min and 250 mm/min. Microstructure observation of welded area was studied by using optical microscope. Equiaxed grains were observed at the TMAZ and stir zone indicating fully plastic deformation. Tool pin diameter ratio 6/1 causes low heat input to the material because of small contact surface between tool surface and stirred materials compared to other tool pin diameter ratio. The grain size of stir zone increased with increasing of ratio of rotational speed to transverse speed due to higher heat input. It is observed that worm hole is produced when excessive heat input is applied. To evaluate the mechanical properties of this specimen, tensile test was used in this study. Welded specimens using taper pin ratio 6:1 shows higher tensile strength compared to other taper pin ratio up to 204 MPa. Moreover, specimens using taper pin ratio 6:1 showed better tensile strength with 500 rpm of rotational speed and 150mm/min welding speed.

Keywords: Friction stir welding, magnesium AZ31, cylindrical taper tool, taper pin ratio.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1124565

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References:


[1] R. S. Mishra and Z. Y. Ma, “Friction stir welding and processing,” Mater. Sci. Eng. R Reports, vol. 50, no. 1–2, pp. 1–78, Aug. 2005.
[2] W. M. U. Thomas, E. D. Nicholas, A. Hall, and C. Cb, “Friction stir welding for the transportation industries,” vol. 18, pp. 269–273, 1998.
[3] M. Nourani, “Taguchi Optimization of Process Parameters in Friction Stir Welding of 6061 Aluminum Alloy: A Review and Case Study,” Engineering, vol. 03, no. 02, pp. 144–155, 2011.
[4] C. B. Jagadeesha, “Dissimilar friction stir welding between aluminum alloy and magnesium alloy at a low rotational speed,” Mater. Sci. Eng. A, vol. 616, pp. 55–62, Oct. 2014.
[5] P. J. Ramulu, R. G. Narayanan, S. V. Kailas, and J. Reddy, “Internal defect and process parameter analysis during friction stir welding of Al 6061 sheets,” Int. J. Adv. Manuf. Technol., vol. 65, no. 9–12, pp. 1515–1528, Jun. 2012.
[6] K. Elangovan and V. Balasubramanian, “Influences of tool pin profile and tool shoulder diameter on the formation of friction stir processing zone in AA6061 aluminium alloy,” Mater. Des., vol. 29, no. 2, pp. 362–373, Jan. 2008.
[7] P. Motalleb-nejad, T. Saeid, a. Heidarzadeh, K. Darzi, and M. Ashjari, “Effect of tool pin profile on microstructure and mechanical properties of friction stir welded AZ31B magnesium alloy,” Mater. Des., vol. 59, no. October 2015, pp. 221–226, 2014.
[8] Y. C. Chen and K. Nakata, “Friction stir lap joining aluminum and magnesium alloys,” Scr. Mater., vol. 58, no. 6, pp. 433–436, Mar. 2008.
[9] A. A. M. da Silva, E. Arruti, G. Janeiro, E. Aldanondo, P. Alvarez, and A. Echeverria, “Material flow and mechanical behaviour of dissimilar AA2024-T3 and AA7075-T6 aluminium alloys friction stir welds,” Mater. Des., vol. 32, no. 4, pp. 2021–2027, Apr. 2011.
[10] N. H. Othman, L. H. Shah, and M. Ishak, “Mechanical and microstructural characterization of single and double pass Aluminum AA6061 friction stir weld joints,” IOP Conf. Ser. Mater. Sci. Eng., vol. 100, p. 012016, 2015.
[11] N. a. a. Sathari, a. R. Razali, M. Ishak, and L. H. Shah, “Mechanical Strength of Dissimilar Aa7075 and Aa6061 Aluminum Alloys Using Friction Stir Welding,” Int. J. Automot. Mech. Eng., vol. 11, no. JUNE, pp. 2713–2721, 2015.
[12] W. J. Arbegast, “Friction Stir Joining: Characteristic Defects,” no. October, 2003.
[13] A. S. Babu and C. Devanathan, “An Overview of Friction Stir Welding,” Int. J. Res. Mech. Eng. Technol., vol. 3, no. 2, pp. 259–265, 2013.
[14] A. Lakshminarayanan, V. Balasubramanian, and M. Salahuddin, “Microstructure, Tensile and Impact Toughness Properties of Friction Stir Welded Mild Steel,” J. Iron Steel Res. Int., vol. 17, no. 10, pp. 68–74, 2010.
[15] A. K. Lakshminarayanan and V. Balasubramanian, “Assessment of sensitization resistance of AISI 409M grade ferritic stainless steel joints using Modified Strauss test,” Mater. Des., vol. 39, pp. 175–185, 2012.
[16] D. G. Hattingh, C. Blignault, T. I. van Niekerk, and M. N. James, “Characterization of the influences of FSW tool geometry on welding forces and weld tensile strength using an instrumented tool,” J. Mater. Process. Technol., vol. 203, no. 1–3, pp. 46–57, Jul. 2008.
[17] H. I. Dawood, K. S. Mohammed, and M. Y. Rajab, “Advantages of the Green Solid State FSW over the Conventional GMAW Process,” Adv. Mater. Sci. Eng., vol. 2014, pp. 1–10, 2014.
[18] D. Lohwasser and Z. Chen, Friction stir welding: From basics to applications. Cambridge, England: Woodhead Publishing Limited, 2010.
[19] S. Rajakumar, C. Muralidharan, and V. Balasubramanian, “Establishing empirical relationships to predict grain size and tensile strength of friction stir welded AA 6061-T6 aluminium alloy joints,” Trans. Nonferrous Met. Soc. China, vol. 20, no. 10, pp. 1863–1872, 2010.