Effect of scanning speed on microstructure and texture of laser surface remelted 1050 Al alloy

A typical commercial Al alloy (1050) sheet was subjected to laser surface remelting (LSR) treatment at 400 W and different scanning speeds (2 and 8 mm/s), with dedicated microstructural and textural characterization made for original and LSRed specimens by using multiple characterization techniques. Results show that the as-received material has a typically recrystallized structure consisting of near-equiaxed grains (average grain size (20.4 & PLUSMN;15.4) & mu;m) and many submicron second phase particles (SPPs). After the LSR treatment, remelting layers of the 2 mm/s and 8 mm/s specimens are mainly composed of columnar grains (with dense fine SPPs inside them), which are coarser than the near-equiaxed grains in the substrate. As the laser scanning speed increases from 2 to 8 mm/s, the depth of the remelted layer is evidently reduced, with the average width of the columnar grains decreasing from (38.0 & PLUSMN;4.3) to (33.9 & PLUSMN;2.0) & mu;m. Meanwhile, the SPPs inside grains are significantly refined with largely increased number density. The LSR does not change the main textural characteristic ({100}& LANGBRAC;001 & rang; cube component) of the as-received sheet but leads to the significantly increased textural intensity.

Automated summary

A typical commercial Al alloy 1050 sheet was treated with laser surface remelting (LSR) at different scanning speeds. The remelting layer consists of columnar grains with dense fine SPPs, and the depth of the layer decreases as the scanning speed increases.