Advantages of the Green Solid State FSW over the Conventional GMAW Process

Figure 9

Optical images reveal the microstructures of different welding zones on Al-Al butt welded joint performed by the FSW technique at a rotational speed of 1750 rpm. (a) BM, (b) NZ, (c) NZ and TMAZ, and (d) TMAZ and HAZ 100x magnification.

(a)

(b)

(c)

(d)