Pulsed CO2 laser ablation of polished steel and titanium nitride-coated steel

The interaction of a Transversely Excited Atmospheric (TEA) CO2 laser, pulse duration less than 100 ns, with austenitic stainless steel-AISI 316 and low thickness coating of titanium-nitride (TiN) deposited on steel are considered. The results have shown that steel as well as coating had been modified by TEA CO2 laser beam. Compared to steel, TiN have shown more diverse changes in the bombarded area: crater like form, solidified boundary and droplets. On austenitic stainless steel--wall material of the vacuum vessel for a fusion reactor--different mechanism of surface degradation was found. A qualitative description comprises: surface corrugation, cracking and resolidified.