Effect of Nd-YAG laser treatment on corrosion behavior of AISI316L stainless steel in artificial saliva solution

Abstract

This work aims to study the effect of Nd-YAG laser treatment on surface modification and corrosion behavior of AISI 316L stainless steel which is the most widely used as implant bio material in the artificial saliva solution at 37 ±1°C. The samples were irradiated with Nd:YAG laser with various pulse repetition rates (or frequencies) of 1,3 and 6 Hz and with two wavelengths of 1064 nm and 532 nm at fixed energy of 1000 mj. Microstructure examinations by optical and SEM were performed before and after laser treatment. Corrosion tests were carried out by using potentiostat instrument and the corrosion rate was measured by Tafel extrapolation method, also cyclic polarization was done to study the active- passive behavior of stainless steel 316L in saliva solution. It has been found that the treated samples at different laser conditions have hardness higher than that of untreated sample. The results showed that the hardness increased slightly with decreasing the pulse repetition rate or frequency from 6 to 1 Hz at 1064nm, also a surface modification and grain refinement were noticed. Corrosion results indicated that the treated samples with 1Hz with 532 nm and 1064 nm showed higher corrosion resistance than untreated base alloy and other treated samples.