Experimental and numerical studies on ultra high rotational speed micro friction stir welding

Abstract

Friction stir welding (FSW) is a solid-state welding technology developed and patented newlinein 1991 by The Welding Institute (TWI), UK. The process was developed for welding newlinealuminium and its alloys, and later extended its application to magnesium, titanium, newlinecopper, steel, plastics, metal matrix composites and dissimilar combination of the metals. newlineThe significance of this technology can be gauged from the fact that NASA used it to newlineweld components of a new-generation rocket s (Space Launch System (SLS)) fuel tank newlineand in the Orion crew module for the 2024 manned lunar project called Artemis. newlineIn the present research work, a novel variant called Ultra-High Rotational Speed newlineMicro friction stir welding (UHRSand#956;FSW) is proposed for welding thin aluminium sheets. newlineWelding of thin sheets is very difficult, even with modern joining processes. Though newlineand#956;FSW is a technology developed for joining ultra-thin sheets, it is associated with several newlinechallenges like insufficient heat generation, increased heat loss from the workpiece, newlineproblems associated with the micro tool, thinning of the workpiece, generation of micro newlinedefects, and fixturing and clamping issues. This research work attempts to study newlineUHRSand#956;FSW using experimental investigation and numerical simulation. The research newlinework is divided into four major stages. The first stage illustrates the development of a newlinelow-cost, light-duty UHRSand#956;FSW setup. The facility is developed using a commercial newlineCNC router, and the necessary attachment for performing and#956;FSW is fabricated using an newlinein-house facility. This stage also discusses the development of a high precision and#956;FSW newlinetool, clamping and fixturing system, and temperature and process force measurement newlinesystem.