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The demand for aluminium alloys has been increasing in almost all the fields. In this study, the friction stir welding (FSW) of similar aluminium alloy AA 8011-h14 has been presented using three levels of tool rotational speed (n), tool tilt angle (ϴ) and tool feed (f). The purpose of this paper is to study the effect of welding parameters on various properties and time-temperature plots.

FSW was carried out using the L-9 orthogonal array of welding parameters generated using the Taguchi approach. Visual inspection and radiography testing were conducted to detect the surface and volume defects, respectively. Taguchi analysis was carried out to get optimised welding parameters for tensile testing. The microstructural analysis was carried out for the specimen possessing maximum tensile strength and the obtained grain structures were compared with the microstructure results of the base material. The peak process temperatures were noted and time-temperature plots were analysed for the varying parameters. The maximum value of hardness was recorded and analysed.

Visual inspection and radiography testing confirmed defect-free joints. The maximum tensile strength achieved was 84.44 MPa with 64.95 per cent efficiency. The optimised parameters obtained using Taguchi analysis for tensile testing were 1,500 rpm, 1° and 50 mm/min. Microstructure analysis for the specimen possessing maximum tensile strength revealed fine and equiaxed grains in the nugget zone. Time-temperature plots suggested the maximum temperature of 389 °C on the advancing side. A maximum hardness value of 36.4 HV was obtained in the nugget zone.

As per the knowledge of the authors, this study is the first attempt for the detailed experimental analysis on the FSW of this particular aluminium alloy AA 8011-h14.

Electron-beam welding has been widely used in industry to join different titanium alloys (Ti-6Al-4V) components. During welding production defects, such as porosity, lack of penetration or thinning are often observed. High-cycle fatigue (HCF) tests have been performed on welded specimens to understand the effect of weld defects on fatigue capabilities. The fatigue life of different types of “defective” welds has been compared against a non-welded reference specimen.

The results of the experimental campaign have been correlated with finite elements models.

It is concluded the geometry produced by the weld process, e.g. toe radius and under-bead shape, and the related stress raisers play a relevant role on fatigue capabilities of welds. This conclusion is valid only for a Ti-6Al-4V T-joint weld and only for flaw initiation. Knock down in materials properties has not been considered.

There is a lack of HCF fatigue data for welds of this geometry and material in the open literature. The paper is of relevance for industrial application and practical interest, although a lot more validation tests are required to draw a final conclusion.