Microstructural Evolution in Friction Stir Welded 1050 Aluminum and 6061 Aluminum Alloy

Abstract

The microstructure of friction stir welded 1050 aluminum and 6061 aluminum alloy was observed by a metallographic technique, transmission electron microscopy, electron backscatter diffraction pattern and optical microscopy. In the stir weld zone, the microstructure of welded 1050 aluminum was significantly different from that of the welded 6061 aluminum alloy. In the case of welding 1050 aluminum, there was a comparatively uniform microstructure in the stir weld zone, not a wedge-shaped microstructure formed in a stir welded 6061 aluminum alloy. EBSD indicated that there was almost same fraction of low angle boundaries among the thermo mechanically affected zone in welded 1050 aluminum and 6061 aluminum alloy. In the stir weld zone, equiaxed grains were created and the grain size of 1050 aluminum was little larger than that of 6061 aluminum alloy, suggesting that precipitates pinning effect affects the dynamic recrystallization in the stir weld zone.

Effect of Heat Input Conditions on Microstructure and Mechanical Properties of Friction-Stir-Welded Pure Copper

“…Grain boundary characteristics have significant meaning for investigating the recrystallization and superplasticity mechanisms. [18][19][20][21][22] It was reported that the percentage of the HAGBs in the SZ of FSW aluminum alloys was higher than in that processed by conventional thermal working techniques. [18] Liu et al [19] indicated that for FSW cold-rolled 1050 aluminum alloy, the percentages of the HAGBs of the PM and the SZ were 32 and 70 pct, respectively.…”

“…[18][19][20][21][22] It was reported that the percentage of the HAGBs in the SZ of FSW aluminum alloys was higher than in that processed by conventional thermal working techniques. [18] Liu et al [19] indicated that for FSW cold-rolled 1050 aluminum alloy, the percentages of the HAGBs of the PM and the SZ were 32 and 70 pct, respectively. Mishra and Mahoney, [20] Norman et al, [21] and Liu et al [22] reported that in the SZ of FSW aluminum alloys, the percentage of the HAGBs is 85 to 97 pct.…”

Strain Rates and Grain Growth in Al 5754 and Al 6061 Friction Stir Spot Welds

“…[8] The tool penetration process and the factors determining weld mechanical properties have been investigated during spot welding of Al-alloy and Mgalloy sheet materials. [9][10][11][12] Although the microstructural features and mechanical properties of Al 5754 and Al 6061 friction stir seam welds have been studied extensively, [13][14][15][16][17][18][19][20][21] this is not the case in Al 5754 and Al 6061 friction stir spots welds made using a range of tool rotational speed settings.…”