AVS 51st International Symposium
    Advanced Surface Engineering Tuesday Sessions
       Session SE-TuP

Paper SE-TuP8
Development of Amorphous Layered Structures by Laser Irradiation for Enhanced Corrosion Resistance

Tuesday, November 16, 2004, 4:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: J.M. Fitz-Gerald, University of Virginia
Authors: J.G. Hoekstra, University of Virginia
P.M. Mackey, University of Virginia
N. Ünlü, University of Virginia
G.J. Shiflet, University of Virginia
J.R. Scully, University of Virginia
J.M. Fitz-Gerald, University of Virginia
Correspondent: Click to Email
Al and Fe based amorphous materials attract attention for their desirable mechanical hardness and corrosion resistance. This study investigated the atomic scale relationships of amorphous layer formation as a function of chemistry and pulsed laser irradiation conditions in Al-Co-Ce and Fe-Mo-Cr-Mo-C-B alloys. The primary objective was to laser surface modify a continuous, homogenous, amorphous layer on a crystalline substrate. Irradiation of a material with a short laser pulse, 3-100 ns, establishes rapid melting and solidification velocities at the surface, 10@super 7@-10@super 8@ K/s and 10@super -1@-10@super 1@ m/s respectively. A KrF excimer laser (@lambda@=248 nm, 25 ns at FWHM, 15 Hz) operating with fluences ranging from 0-10 J/cm@super 2@ irradiated a target surface with corresponding velocity between 0-50 mm/s in a controlled atmosphere ranging from 50-500 mTorr. Characterization was performed by SEM, EDS, XRD, and electrochemical analysis. The resulting microstructures were correlated with electrochemical analysis and devitrification behavior.