Quantifying crystallographic texture in the probe-dominated region of thick-section friction-stir-welded aluminium

Development of Microstructure and Crystallographic Texture in a Double-Sided Friction Stir Welded Microalloyed Steel

“…The effective tapering of the weld was measured to be 47° which is only slightly greater than the actual 45° tapering of the probe. A similar observation has been reported for aluminium [25].…”

“…A clear systematic rotation of the texture can be observed across the SZ, from far RS to the far AS (Figure 7 a). Similar observations have been reported for aluminium [25] and a titanium alloy that like the material investigated in this study, undergoes phase transformation [55]. This implies that the texture within TMAZ and SZ are equivalent, and can be related to each other by two rotation angles; a rotation angle ( ) about the ND and a constant tilt angle ( ) about a direction perpendicular to the ND.…”

“…The band structure in Figure 7 is not as sharp and distinguishable as those reported for aluminium [25], possibly due to the design of the probe. The formation of bands is attributed to features like threads, flutes and flats in the probe [53][54].…”

“…Studying texture evolution during FSW of aluminium alloys showed that {110}<110> and {114}<221> shear components were dominant with respect to the local shear reference frame [23][24]. Later study on aluminium showed that the texture is entirely simple shear / and components with / in alternating bands, constructing the onion ring structure, across the whole weld [25]. A well-defined shear texture is reported for pure iron subjected to friction stir processing (FSP) [21].…”

Thermal Stir Welds in Titanium

“…It also exhibits the expected rotation in shear direction across the weld that arises from variations in the tool tangent orientation. [25][26][27] Both EBSD images and textures were acquired across the weld and into the base plate on both sides of the weld to observe variations in microstructure and texture. The color indicates the crystallographic orientation of each grain that is aligned with the plate normal (the tool rotation axis), revealing a relatively constant orientation of red and blue grains across the weld nugget surrounded by a narrow transition region (boxed regions) and then the primarily orange base plate.…”