Influence of Surface Pre-treatments on Laser Welding of Ti6Al4V Alloy

In the present study, Ti6Al4V samples have been welded under conduction regime by means of a high power diode laser. The main objective of the work has been to determine the actual influence of the surface pre-treatments on the laser welding process. Thus, six different pre-treatments were applied to Ti6Al4V samples before performing bead-on-plate and butt welding treatments. The depth, width, microstructure, and microhardness of the different weld zones were deeply analyzed. Grinding, sandblasting, and chemical cleaning pre-treatments lead to welds with the highest depth values, presenting high joint strengths. Treatments based on the application of dark coatings generate welds with lower penetration and worse mechanical properties, specially the graphite-based coating.