Influence Of Post-weld Treatments Research Articles

Influence of Post Weld Heat Treatment in Friction Stir Welding of AA6061 and AZ61 Alloy

The increasing application of automotive aerospace materials, such as Magnesium alloys and Aluminum alloys is challenging the joining processes of dissimilar metals and alloys. Friction Stir Welding (FSW) being one among the recent research novelty area on the material joining processes. This paper involves to study the influences of post weld treatment of Aluminum AA6061 and AZ61 through Non Destructive Testing (NDT) methods. The FSW butt joints are post weld heat treated with three different temperatures (100, 300 and 400°C) and aged for 1 hour, three hours and five hours periods. Its effects are analyzed by the study of eddy-current test, micro hardness evaluation and Scanning Electron Microscopy (SEM) analysis. The analysis infers that the aging period also plays a major role as that of temperature in the improvement of joint efficiency. A satisfactory correlation exists between the eddy-current test’s impedance values, micro hardness values and SEM analysis.

Influence of post weld treatments on the fatigue behaviour of Al-alloy welded joints

In this paper the influence of different post welding treatments, such as ageing or shot peening, on the fatigue behaviour of Al-alloy welded joints was investigated. The analysed joints were candidates for car structural applications. Several four point bending fatigue tests were conducted on GMAW specimens subjected to different post weld treatments. The residual stress field acting on specimens was measured by the X-ray diffraction (XRD) technique. The results of tests were discussed with the aid of a finite element model of the specimen aimed to calculate the actual fatigue cycle, also taking account of residual stresses and of their redistribution during the test. This allowed to characterize the fatigue resistance of the joints, taking account of the effective stress acting in the region of crack initiation.