**Appendix B. Scanning Electronic Microscopy (SEM) to Detect Decohesionated Layer in the Upper Edge of the Surface**

Figure A2 shows the surface of deposited material along the thickness for samples nº 2 to 7. The resin embedding the sample has not to be confused with the formation of the decohesionated layer that was only found in Sample nº1, using MIG conventional without CMT.

(a) Sample nº 2 (CMT) (b) Sample nº 3 (CMT Adv. pol. 0)

(c) Sample nº 4 (CMT Adv. pol. 0) (d) Sample nº 5 (CMT Adv. pol.ȱƺ5)

(e) Sample nº 6 (CMT Adv. pol. +5) (f) Sample nº 7 (CMT)

**Figure A2.** SEM images showing no decohesionated layer formation in the upper edge of the surface. (**a**) Sample nº 2, CMT process; (**b**) Sample nº 3, CMT Adv. pol. 0; (**c**) Sample nº 4, CMT Adv. pol. 0; (**d**) Sample nº 5, CMT Adv. pol. −5; (**e**) Sample nº 6, CMT Adv. pol. +5; (**f**) Sample nº 7, CMT Cont.
