On the debris formation during atmospheric pressure plasma-assisted laser engraving of stainless steel
Abstract
In this chapter, comparative studies on the debris formation during pure laser engraving and atmospheric pressure plasma-assisted laser engraving, a.k.a. laser-plasma-hybrid engraving, of stainless steel, are presented. It is shown that the width and area of debris can be significantly reduced by introducing such plasma simultaneously to the laser process, and a higher engraving depth can be achieved in the same way. When applying the plasma subsequently to laser engraving, debris formation is not notably affected. The above-mentioned phenomena are rather linked to chemical reactions between the evaporated metal and radicals contained in the plasma during the ablation process. This is confirmed by the presented X-ray photoelectron spectroscopic measurements. It is shown that in the case of laser-plasma-hybrid engraving, the resulting debris features less oxygen due to the applied chemically reducing plasma as expressed by a decrease of the O/Fe-ratio by a factor of 1.3. The reduction of debris as a result of laser-plasma-hybrid engraving is also shown for other materials.
