An experimental investigation on friction stir welding of aluminium alloy 6063 t6 pipes

Abstract

Pipes are hollow tubular sections used predominantly for fluid conveyance and structural applications. Their major applications include transportation of gases, water and other fluids. Aluminium Alloy (AA) 6063-T6 pipes are used widely for fluid conveyance in food processing industries and for structural purposes in aerospace and architectural applications. For such engineering applications, these pipes are required to be cut and joined to fit the requisite design. The quality of pipe joints has a significant and direct impact over the performance of the pipe, especially for pressurized pipeline systems. The most common methods used to fabricate AA 6063-T6 pipe weld joints are fusion welding techniques such as Gas Tungsten Arc Welding (GTAW), otherwise known as Tungsten Inert Gas (TIG) welding. The major drawback in fusion welding techniques is the piling up of residual stresses at the weld zone, which reduces the mechanical performance of the weldment to a more considerable extent. The latest advent of technologies has paved a way for the incorporation of new welding processes like Friction Stir Welding (FSW), which produces high-performance weld joints. This FSW, being a solid-state welding process, is well suited for joining all types of aluminium alloys. In the past two decades, extensive researches have been carried out on the effect of FSW process parameters in almost all versions of aluminium alloys. From literature survey, it is evident that the FSW process has the potential to replace the fusion welding techniques in joining aluminium alloy materials. This present research aims to harvest this potential and apply it for producing high strength aluminium alloy pipe joints newline