Development of a corrosion microprobe for monitoring of the effects of laser micro welding on the properties of Ti-Nb-xSn and Ni-Ti alloys

Abstract

The goaql of this project is to develop a corrosion microprobe which allows the accessing to the electrochemical behavior of regions with micrometric dimensions. The prototype will be used to characterize the influence of the laser micro welding on Ti-35Nb-xSn and Ni-Ti alloys, both characterized by shape memory effect superelasticity and application as biomaterial. Welding processes are recognized by compromising corrosion resistance. Welding usually changes the structure and local composition, causing corrosion around the weld bead and the heat affected zone. The laser micro welding results in a CS width less than 0.5 mm and a HAZ with half of this dimension, which makes difficult to differentiate the effects of welding on these two regions and mainly, the galvanic couple between them. The corrosion resistance parameters obtained by the DC and AC techniques will be compared with the microstructure, compositional changes, presence of phases and with the mechanical properties in the region of the micro welding. (AU)