The Effect of Friction Stir Processing on Microstructure and Mechanical Properties of Al6061-T6 Aluminium Alloy

Document Type : Research Paper


1 Daneshpajoohan Higher Education Institute, Isfahan, Iran. Ph.D. Graduated from Isfahan University of Technology, Isfahan, Iran.

2 Department of Materials Engineering, Isfahan University of Technology, Isfahan, Iran



In this research, the influence of friction stir processing (FSP), on structural and mechanical properties of Al6061-T6 was investigated. Friction stir processing with tool rotational rate (ω) of 630, 800 and 1000rpm and traveling speed (v) of 50,100,160 and 200mm/min was employed on 13mm thick Al6061-T6. Results indicated that FSP decreases grain size from 78µm to 6µm because of the dynamic recrystallization. The finest grain size was obtained at the rotational rate of 630 rpm and traveling speed of 100 mm/min. Results have recommended that when the ratio of ω/v was less than 5(rpm/mm.min-1), due to inadequate heat input, microscopic voids were produced in nugget zone (NZ). Microhardness and tensile strength in the stir zone decreased, but elongation raised compared to those for the base metal. This is due to the loss of hardening precipitates during FSP.With increasing the tool travelling speed, grain size in nugget NZ and mechanical properties were improved. The best mechanical properties at NZ have been obtained at ω=630 rpm and v=100 mm/min due to the finest grain size.


  1. 1.Das S. Design and Weight Optimization of Aluminium Alloy Wheel. International Journal of Scientific and Research Publication. 2014;4:1-12.


    1. Raj RJ, Selvam PP, Pughalendi M. A Review of Aluminum Alloys in Aircraft and Aerospace Industry. Journal of Huazhong University of Science and Technology. 2021; 50: 1-10.


    3.Basavegowda N, Mandal TK, Baek KH. Bimetallic and Trimetallic Nanoparticles for Active Food Packaging Applications: A Review.Food and Bioprocess Technology. 2020; 13:30–44.


    4.Chandla NK, Kant S, Goud MM. Mechanical, tribological and microstructural characterization of stir cast Al-6061 metal/matrix composites-a comprehensive review. Sadhana. 2021; 46: 1-38.


    5.Ogunsanya OA, Akinwande AA, Balogun OA, Romanovski V, Kumar M S. Mechanical and damping behavior of artificially aged Al 6061/TiO2 reinforced composites for aerospace applications.Particulate Science and Technology. 2022; 41:196-208.DOI:10.1080/02726351.2022.2065652


    6.Charit I, Mishra RS. Low temperature super plasticity in a friction-stir-processed ultrafine grained Al–Zn–Mg–Sc alloy. Acta Materialia. 2005;53: 4211–4223.


    7.Zainelabdeen IH, Al-Badour FA, Adesina AY, Suleiman R, Ghaith FA. Friction stir surface processing of 6061 aluminum alloy for superior corrosion resistance and enhanced microhardness. International Journal of Lightweight Materials and Manufacture. 2023; 6: 129-139.


    1. Mehta KM, Badheka VJ. Effect of friction stir processing passes on wear properties of Al-6061-T6 alloy. Journal of the Brazilian Society of Mechanical Sciences and Engineering. 2021; 43.


    9.Cui GR, Ma ZY, Li SX. The origin of non-uniform microstructure and its effects on the mechanical properties of a friction stir processed Al-Mg alloy. Acta Materialia. 2009; 57: 5718-5729.


    10.Frigaard Ø ,Grong Ø ,Midling OT. A Process Model for Friction Stir Welding of Age Hardening Aluminum Alloys. Metallurgical and Materials Transactions A. 2001; 32: 1189-1200.


    1. Frigaard Ø, Grong Ø, Bjørneklett B, Midling OT. Modelling of the Thermal and Microstructural Fields During Friction Stir Welding of Aluminum Alloys. Proceeding1st International Symposium on Friction Stir Welding, The Welding Institute, TWI; 1999 June; Thousand Oaks, CA, Cambridge, United Kingdom.


    12.Murr LE, Flores RD, Flores OV, McClure JC, Liu G, Brown D. Friction-stir welding: microstructural characterization. Materials Research Innovations. 1998; 1: 211-223.


    13.Scialpi A, De Filippis LAC, Cavaliere P. Influence of shoulder geometry onmicrostructure and mechanical properties of friction stir welded 6082aluminium alloy. Materials & Design. 2007; 28:1124–1129.


    14.Woo W, Choo H, Brown DW, Vogel SC, Liaw PK, Feng Z. Texture analysis of a friction stir processed 6061-T6 aluminum alloy using neutron diffraction. Acta Materialia. 2006; 54: 3871–3882.


    15.Svensson LE, Karlsson L, Larsson H, Karlsson B, Fazzini M, Karlsson J. Microstructure and mechanical properties of friction stir welded aluminium alloys with special reference to AA 5083 and AA 6082.Science and Technology of Welding and Joining. 2000; 5: 285–296.


    16.Hassan KAA, Prangnell PB, Norman AF, Price DA, Williams SW. Effect of welding parameters on nugget zone microstructure and properties in high strength aluminium alloy friction stir welds. Science and Technology of Welding and Joining. 2013; 8:257–268.


    1. Mishra RS, Mahoney MW. Friction Stir Welding and Processing. ASM International: American Society of Material; 2007.


    18.Pareek M, Polar A, Rumiche F, Indacochea JE. Mechanical properties and corrosion resistance of friction stir welded AZ31B-h24 magnesium alloy. Proc. 7th International Conference on Trends in Welding research; 2005; USA.


    19.Chang CI, Lee CJ, Huang JC. Relationship between grain size and Zener–Holloman parameterduring friction stir processing in AZ31 Mg alloys. Scripta Materialia. 2004; 51: 509–514.


    20.Mirzadeh H. Simple physically-based constitutive equations for hot deformation of 2024 and 7075 aluminum alloys. Transactions of Nonferrous Metals Society of China. 2015; 25: 1614-1618. DOI:10.1016/S1003-6326(15)63765-7.


    21.Humphreys JF. Recrystallization and Recovery. Materials Science and Technology. 2006: 373-398.


    1. Harris D, Norman AF. Properties of Friction Stir Welded Joints. A Review of the Literature, EUROSTIR; 2003. Progress report presented at the 6th PSG Meeting.


    23.Scialpi A, De Giorgi M, De Filippis LAC,Nobile R, Panella FW. Mechanical analysis of ultra-thin FSW joined sheets with dissimilar and similar materials. Materials & Design. 2008; 29:928–936.


    1. Grong O, editor. Metallurgical modelling of welding. The Institute of Materials, London; 1997.


    25.Moreira PMGP,Santos T, Tavares SMO, Richter-Trummer V, Vilaça P, de Castro PMST. Mechanical and metallurgical characterization of friction stir welding joints of AA6061-T6 with AA6082-T6.Materials & Design. 2009; 30:180–187.