ISSN:
1572-9540
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Steel plates (St 14-05) of 1.5 mm thickness and coated with 1.5 μm of ironzinc-phosphatehydrate (ASTM 29-1429) were irradiated with an XeCl-excimer laser (Siemens XP 2020) at energy densities of 20–80 mJ/mm2 and with 2–32 pulses per spot. Depth-sensitive Mössbauer spectroscopy was carried out by means of conversion electron (CEMS) and conversion X-ray (CXMS) Mössbauer spectroscopy in order to determine the phases produced by the excimer laser treatment. Although the phosphate layer is mainly ablated during the laser treatment, there is a significant formation of Fe2P. The phosphorous phase and the wüstite, with changing stoichiometries, were found in the very surface (CEMS). In deeper layers and in correlation with the energy density and the number of pulses, austenite was found in surprisingly high amounts (CEMS and CXMS). The austenite was found to be nitrogen austenite. The high Fe-N austenite content as well as the presence of some ferromagnetic Fe-N phase (ε-Fe2+xN) must be ascribed to an unexpectedly high nitriding effect during the laser treatment.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02065779
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