Abstract
Among available processing technologies of heat-treatable aluminum alloys such as the 2219 aluminum alloy, the use of both friction stir welding (FSW) as joining technology and electromagnetic forming (EMF) for plastic formation technology have obvious advantages and successful applications. Therefore, significant potential exists for these processing technologies, both of which can be used on the 2219 aluminum alloy, to manufacture large-scale, thin-wall parts in the astronautic industry. The microstructure and mechanical properties of 2219 aluminum alloy under a process which compounded FSW, heat treatment, and EMF were investigated by means of a tensile test as well as via both an optical microscope (OM) and scanning electron microscope (SEM). The results show that the reduction of strength, which was caused during the FSW process, can be recovered effectively. This can be accomplished by a post-welding heat treatment composed of solid solution and aging. However, ductility was still reduced after heat treatment. Under the processing technology composed of FSW, heat treatment, and EMF, the forming limit of the 2219 aluminum alloy decreased distinctly due to the poor ductility of the welding joint. A ribbon pattern was found on the fractured surface of welded 2219 aluminum alloy after EMF treatment, which was formed due to the banded structure caused by the FSW process. Because of the effects of induced eddy current in the EMF process, the material fractured, forming a unique structure which manifested as a molten surface appearance under SEM observation.
Highlights
2219 aluminum alloy is a suitable material for manufacturing large-scale, thin-wall parts in the astronautic industry, such as the cryogenic fuel tank of launch vehicles, thanks to its characteristics of good weldability, corrosion stability as well as its superior qualities in specific strength and thermal stability [1,2]
The thermal effect and the plastic flow during Friction stir weld (FSW) treatment causes an expediting of precipitation during heat treatment, and the inhomogeneous structure of the welding joint will reduce the formability of 2219 aluminum alloy during the electromagnetic forming (EMF) process [9]
The EMF treatment was performed on the 2219 aluminum alloy samples, which were processed under the optimal compound technology of FSW and heat treatment
Summary
2219 aluminum alloy is a suitable material for manufacturing large-scale, thin-wall parts in the astronautic industry, such as the cryogenic fuel tank of launch vehicles, thanks to its characteristics of good weldability, corrosion stability as well as its superior qualities in specific strength and thermal stability [1,2]. A heat treatment composed of solid solution and aging can produce a dispersive distribution of precipitated phase, which can bring a remarkable improvement in the mechanical properties of 2219 aluminum alloy [6]. FSW technology, which can create solid bonding through the frictional effects of the tool shoulder and the stirring effect of the pin, has been widely applied in the manufacture for large-scale parts of aluminum alloys. The thermal effect and the plastic flow during FSW treatment causes an expediting of precipitation during heat treatment, and the inhomogeneous structure of the welding joint will reduce the formability of 2219 aluminum alloy during the EMF process [9]. Discussed to study the influences of FSW treatment on the forming behavior of 2219 aluminum alloy during the EMF process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
