AVS 52nd International Symposium
    Advanced Surface Engineering Tuesday Sessions
       Session SE-TuP

Paper SE-TuP3
Laser Processing of Crystalline Technologically Relevant Glass-Forming Alloys for Enhanced Corrosion Resistance

Tuesday, November 1, 2005, 4:00 pm, Room Exhibit Hall C&D

Session: Advanced Surface Engineering Poster Session
Presenter: J.M. Fitz-Gerald, University of Virginia
Authors: J.M. Fitz-Gerald, University of Virginia
J.G. Hoekstra, University of Virginia
M.A. Jakab, University of Virginia
S.J. Poon, University of Virginia
G.J. Shiflet, University of Virginia
J.R. Scully, University of Virginia
Correspondent: Click to Email
Over the past 25 years, investigations concerning the use of continuous and pulsed lasers for surface modification have met with reasonable success in areas of alloying element modification, enhanced surface hardness, structure manipulation, and improvements in corrosion resistance.@footnote 1@ There are several critical attributes of laser surface modification (LSM) that lead to the formation of an amorphous surface, including the ability to promote near-surface compositional uniformity, and due to the use of a pulsed laser (nanoseconds), rapid solidification at quench rates on the order of 10@super 8@ to 10@super 10@ K/s are possible. Moreover, since only the first few micrometers are re-solidified, LSM presents the opportunity to explore the surface amorphization of materials without sacrificing desirable bulk properties such as strength and toughness. This research focuses on the Al-Co-Ce and Fe-Cr-Mo-Er-C-B alloy systems with enhanced glass forming chemistries. In this research, the homogeneity of the starting crystalline ingot has been found to have a major impact on the ability to form an amorphous surface. The LSM surfaces showed several amorphous characteristics in terms of backscattered imaging, diffraction spectra, and corrosion behavior, all of which are signatures of these classes of amorphous materials. Electrochemical analysis of the modified materials showed increased pitting potentials and several characteristics similar to that of fully amorphous, melt spun metallic glass alloy standards. Characterization was performed with scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), Auger electron spectroscopy (AES), conventional and glancing angle X-ray diffraction (XRD), and electrochemical analysis. @FootnoteText@ @footnote 1@ K.G. Watkins, M.A. McMahon, and W.M. Steen, Mat. Sci. and Eng. 231, p. 55 - 61 (1997).