Shoulder Related Temperature Thresholds in FSSW of Aluminium Alloys

Abstract

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.

Friction Stir Welding/Processing of Mg-Based Alloys: A Critical Review on Advancements and Challenges

“…In this way, they concluded that the AZ31-fly ash composite possesses higher wear resistance as compared to AZ31 alloy [150]. It is evident that FSW and FSP techniques could have beneficial impacts on the mechanical behavior of Mg and other metallic alloys [133,[151][152][153][154][155][156][157][158][159][160][161][162][163][164][165][166][167]. Hence, the mechanical properties of some types of magnesium-based alloys before and after FSP are listed in Table 7.…”

Analysis of Mechanical Properties and Microstructure of Aluminum and Copper Sheet Welding Using Friction Stir Spot Welding Method

“…A study was conducted by Andrade et al on shoulder-related temperature thresholds in FSSW of aluminum alloys. The research results indicate that the temperature in FSSW can be regulated by using an appropriate combination of rotation speed and tool dimensions for aluminum alloys (Andrade et al, 2021). The heat generation in aluminum alloy FSSW was assessed by producing bead-on-plate spot welds with a pinless tool.…”

Experimental and numerical analysis of intermetallics in Al–Mg friction stir welds

“…Friction stir welding (FSW) does not exhibit the melting and solidification phase of joining the materials and so the problems encountered during the fusion welding process will be overcome [9][10][11]. Demonstrations of the joining of dissimilar combinations like Al-Fe [12], Al-Cu [13], Al-Brass [14], and dissimilar Al-Al [15] joints were attempted by various researchers.…”