TY - JOUR
T1 - A new method for isolating plasma interactions from those of the laser beam during plasma nitriding
AU - Black, A. N.
AU - Copley, S. M.
AU - Todd, J. A.
N1 - Funding Information:
The authors would like to acknowledge the assistance of Amar Kamat, Dr. Abdalla Nassar, and Dr. Ravindra Kumar Akarapu for discussions and feedback, and also Scott Kralik for assistance with metallography and imaging. The authors gratefully acknowledge research support from the Office of Naval Research , Grant No: N00014-07-1-0121 , and the National Science Foundation (NSF), which awarded a NSF Graduate Research Fellowship to Amber Black.
Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2017/12
Y1 - 2017/12
N2 - A new method for separating the interactions of a laser plasma from those of a laser beam with a titanium substrate was developed. A laser-sustained plasma (LSP) was generated by striking the plasma on a titanium plate in a flowing nitrogen atmosphere at ambient pressure and subsequently removing the strike plate. The resultant nitrogen plasma was sustained indefinitely around the laser focal plane until the nitrogen gas flow and/or the laser power were switched off. The laser-sustained nitrogen plasma was then used as a “reactor” to study the effects of a nitrogen plasma, independent of the laser beam, when the plasma was brought into close proximity, (2 to 3 mm), parallel to a titanium substrate. There was no interaction of the parallel laser beam with the substrate. Heat, nitrogen and titanium were exchanged between the nitrogen LSP and substrate resulting in melting, nucleation and growth of faceted and dendritic TiN crystals, rectangular hollow TiN morphologies and particulate TiN deposits. Dense TiN layers up to 300 μm thick formed within 5 s. The results demonstrated that compositionally graded layers of nitrogen-enriched titanium, and titanium nitride could be formed very rapidly on model, commercially-pure titanium substrates, with promise for extension to commercial alloys such as Ti-6Al-4V.
AB - A new method for separating the interactions of a laser plasma from those of a laser beam with a titanium substrate was developed. A laser-sustained plasma (LSP) was generated by striking the plasma on a titanium plate in a flowing nitrogen atmosphere at ambient pressure and subsequently removing the strike plate. The resultant nitrogen plasma was sustained indefinitely around the laser focal plane until the nitrogen gas flow and/or the laser power were switched off. The laser-sustained nitrogen plasma was then used as a “reactor” to study the effects of a nitrogen plasma, independent of the laser beam, when the plasma was brought into close proximity, (2 to 3 mm), parallel to a titanium substrate. There was no interaction of the parallel laser beam with the substrate. Heat, nitrogen and titanium were exchanged between the nitrogen LSP and substrate resulting in melting, nucleation and growth of faceted and dendritic TiN crystals, rectangular hollow TiN morphologies and particulate TiN deposits. Dense TiN layers up to 300 μm thick formed within 5 s. The results demonstrated that compositionally graded layers of nitrogen-enriched titanium, and titanium nitride could be formed very rapidly on model, commercially-pure titanium substrates, with promise for extension to commercial alloys such as Ti-6Al-4V.
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U2 - 10.1016/j.matchar.2017.10.011
DO - 10.1016/j.matchar.2017.10.011
M3 - Article
AN - SCOPUS:85032857239
SN - 1044-5803
VL - 134
SP - 143
EP - 151
JO - Materials Characterization
JF - Materials Characterization
ER -