Microstructure and mechanical properties of friction stir lap AA6061-Ti6Al4V welds

Solid-state joining of aluminum to titanium: A review

“…Furthermore, initially, Al 3 Ti was generated at the Al-Ti interface while, TiAl formed at the Ti and Al 3 Ti interface, via the Al diffusion across the Al 3 Ti layer. In their other similar work, 31 it is claimed that maximum lap shear strength was achieved in comparison with past studies. However, the work will be fruitful to compare when experiments were done with the same process condition as can be seen in Table 3.…”

“…It is recommended to keep TPO on Al side to get sound joints. 12,[14][15][16][24][25][26][27]29,31,33,35,36 In addition to this, Zn insert layer with different TPOs in the FSW process revealed that the TPO position restricts the number of ternary materials mechanical mixing (TS: 132 MPa at TPO: 1.6 mm). 61 Similarly, using different TPO with Cu interlayer in FSW process, higher hardness values were achieved at lowest TPO, whereas with more TPO weld defects are formed.…”

“…At constant TRS, interface thickness decreases then increases with an increase in WS. 31 It is found that at optimum interface thickness better tensile properties were attained.…”

“…It is recommended that the higher melting temperature work material should be placed on the AS with the TPO from the interface of the butt joint towards the low melting point temperature work material in butt joint configuration to avoid tool erosion and charring of the low melting point materials, 71 which support most of the literature. 12,[14][15][16][24][25][26][27]31,33,35,36 The TPO plays a crucial role in the Ti fragments formation than the TRS. The quantity of Ti fragments reduced with the reducing TPO from 0.2 to 0.1 mm.…”

“…With this, Al to Ti alloy joining is employed in aerospace, automobile, 1-23 marine, 7,8,16 and defense industries 18,24 where current efforts are being made to ensure more values of strengthto-weight ratio and are attained at an affordable price. For instance, in aircraft manufacturing, the welding of riveted fuselage structures are replaced by skin stringer joints, 23,25 seat track, 22,[25][26][27][28] heat exchangers 7,8 or electric conductors in corrosive media, 29 tubing and pipework of propellant tanks, 30 medical industry, 2 architecture, 1 joining the Al skins to Ti ribs for aircraft, 31 aircraft structural parts, 32 joining of Ti alloy crust and Al alloy honeycomb (wing of airplanes), 27,33 cooling fin employed in aeroplane cabins are made from welding of Al and Ti, 27 experimental NASA YF-12 fighter wings, 27 transportation industries, [34][35][36][37][38] chemical industries, 39 cryogenics, nuclear, and thermal power station. 40 Further, there is another possibility of implementation of hybrid structures [41][42][43] i.e.…”