Biomedical Engineering Reference
In-Depth Information
[49]. The laser surface remelting process results in suppressing of
the pitting corrosion. The improved pitting corrosion resistance is
related with microstructural changes caused by rapid solidiication
after laser remelting. Figure 5.20 shows an example of a single-
track cross section of the laser remelted zone. Material after laser
treatment consists of remelted zone (white), where remelting and
resolidiication occurs, and heat affected zone (light colored semi-
circular) where heating and cooling process occurs without melting
[49]. The width of the remelting zone depends from the laser
scanning speed and was kept in the range of 1.7-2.0 mm. The Ti
surface after laser remelting is shown in Fig. 5.21 [49]. The surface
is relatively lat and the structure of the remelted zone is formed
mainly by the martensitic phase. The corrosion test indicates an
improvement of the corrosion resistance, especially pitting corrosion
achieved by Nd-YAG laser Ti surface remelting.
Figure 5.20
Cross section of a laser surface remelted zone [49].
Figure 5.21
Surface after laser remelting [49].
