Application of acoustic emission technique for online monitoring of friction stir welding process during welding of AA6061-​T6 aluminum alloy

Acoustic Emission (AE) technique has been successfully used to monitor processes like metal cutting, grinding and electron beam welding as a nondestructive evaluation method. Friction Stir Welding (FSW) is a solid state welding that avoids problems assocd. with fusion welding and is used in aerospace industries. An attempt has been made to study the application of AE technique to monitor FSW process by identifying the occurrence of defect while welding is in progress and suggest means to rectify the defect. In this study, aluminum alloy AA6061-​T6 has been used as work piece material. It was obsd. that the nature of AE signals produced during welding are helpful in identifying the occurrence of defects produced. The values of a few AE parameters derived from AE signals were found to be helpful in developing a model for online monitoring of FSW process to produce defect free welds. The model has been successfully validated

OPTIMIZATION OF PROCESS PARAMETERS FOR CONICAL AND CYLINDRICAL TOOLS WITH GROOVES IN FRICTION STIR WELDING PROCESS

Abstract: Friction Stir Welding is a recent emerging welding technology invented by The Welding Institute (TWI) in 1991. This has evolved into a process focused on joining of arcweldable (5xxx and 6xxx) and difficult to weld (2xxx and xxx) aluminum alloys. The present study is aimed to determine the optimum process parameters and identify the most influencing significant parameter along with percentage contribution of each parameter on tensile strength of Friction Stir Welded AA 7075-T6 aluminum joints by conducting specific number of experiments using Taguchi approach. In this study, tool pin profiles having conical and cylindrical head with grooves are used. It has been observed that the tool rotational speed exhibits more influence on tensile strength in both the tools. Further the tool having conical profile results in better joint efficiency than the tool having cylindrical profile. The method described in this paper for the prediction of tensile strength and optimization of process parameters can eliminate the need for performing more experiments on the basis of conventional trial and error method

Fatigue crack growth and fracture toughness behaviour of aluminium lithium alloys

This report presents the experimental result on fatigue13; crack progation(FCP) of 2mm thick Al-Li alloy sheet material also presents the fracture toughness behaviour of 11.5 mm thick Al alloy plate material. The FCP properties of Al-Li alloys compared with the conventional 2mm thick 2024-T3 aluminium alloy comparable strength. Similarly, the fracture toughness data of 2024-T3 Al alloys.Test results of Al-Li alloys are compared with available data of 2024-T3 Al alloys from tests carried out NA