A review on friction stir welding: A sustainable way of manufacturing

Abstract

Abstract Friction stir welding (FSW) process has gained popularity due to its energy efficiency in joining similar or dissimilar materials as compared to traditional way of joining materials and as it involves no use of shielding gas and little harmful emissions due to which it is regarded as ‘green technology’. It’s a solid-state joining process in which plastic deformation takes place to join the similar or dissimilar materials rather than melting. Due to this its applications can be found in the field of industries ranging from aerospace to ship building and rail to electronics. FSW plays a key role in joining many ‘non-weldable’ aluminium alloys such as from 2xxx series alloys (Al-Cu) and 7xxx series alloys (Al-Zn) which is not possible with conventional process leads to softening of weld plates which leads to decrease in the mechanical properties. Hence, the study of various interlayers such as zinc, copper, brass, nickel, tin etc. has become a hot topic for researchers. The joining of dissimilar material is often difficult due to difference in physical properties and composition and hence use of interlayer in FSW helps in effective joining. Insertion of interlayer between the interface of plates to be joined not only enhances the tensile strength of the weld joint but also restricts the excessive formation of hard and brittle intermetallic compounds (IMCs) and leads to controlled formation of fine and uniformly distribution of IMCs and reduces the residual stresses and further increases the joint efficiency. This work contains the review of some important research papers on FSW of similar alloys (Al-Al), dissimilar alloys (Al-Mg), and effects of interlayer on similar alloys (Al/Cu/Al) and dissimilar alloys (Al/Zn/Mg). This paper also throws light on effects of process parameters such as (tool rotation, tool transverse speed, tool materials) on joining of materials by FSW has been discussed along with the suggestions of the researchers.