Effects of process parameters on joint formation and tool wear behavior in friction stir welded TA5 alloy

Friction Stir Welding/Processing of Various Metals with Working Tools of Different Materials and Its Peculiarities for Titanium Alloys: A Review

“…When welding titanium alloys, the weld is predominantly "pool-shaped" (Figure 12a-c [355,370,379]), although other weld shapes are available (Figure 12d [107]), unlike welds of aluminum and magnesium alloys, which have a predominantly elliptical weld shape [268,363,377,[383][384][385][386][387]. Since titanium alloys have low thermal conductivity, the thermomechanical and heat-affected zones in their weldings are extremely small [364,370,378,[384][385][386][387][388][389][390][391][392]. Various authors note that there is no heat-affected zone in the welding of commercially pure titanium [343,[392][393][394], and there is no thermomechanically-affected zone in the welding of Ti6Al4V alloy [385,386,389].…”

“…Tool and titanium alloy contact necessarily lead to interaction at different levels. Mutual diffusion dissolution of the tool and material, formation of secondary phases on the tool surface, formation of the tribological layer, its destruction, and mixing of fragments into the material of the joint or processing zone take place [83,85,106,107,368,370,393,404].…”

“…There are relatively few studies on the structural degradation, wear, and failure of tools made of different materials during friction stir welding or processing [83,85,106,107,343,[368][369][370]. As mentioned earlier, the most studied processes in this field are friction stir welding processes using tools made of tungsten or molybdenum-based alloys, hard alloys, polycrystalline boron nitride, and heat-resistant nickel or cobalt alloys.…”

Role of oscillation frequency and amplitude on the microstructure and properties of linear friction welded nickel aluminium bronze joints

“…The weld zone of joints exhibited enhancement in hardness due to a widmansatten structure caused by greater stirring action by the FSW tool, resulting in overmatched tensile properties. Though friction stir welding can be used, it has disadvantages such as tool wear due to cold conditions during the plunging phase, slower welding rates, and larger welding forces, which mandate rigid and precise welding apparatus for joining high melting temperature materials [15,16].…”

Influence of Different Filler Metals on the Mechanical and Microstructural Characteristics of Arc-Welded Joints Made of Dissimilar Titanium Alloys

“…Therefore, the main heat generated around tool shoulder is difficult to transfer downwards during welding, leading to a large temperature gradient along the thickness. As a result, the achievement of a defect-free joint is generally constrained within a quite narrow process window [8]. Due to the low thermal conductivity of such an alloy, it is difficult to remove heat from the welding zone, and the use of an active liquid cooling system could be required [9].…”