2
Atom scale structure and minor solute exert strong effects on the corrosion properties of ideal solid solution alloys The effects of structural (order–disorder transformation, glass relaxation), chemical (solute clusters, minor solute elements) and structural + chemical defects (solute rich and lean nanocrystals in an amorphous solid solution) on corrosion are investigated using model alloys. Disordered crystalline Fe 50 Pd 50 : The disordered structure has strong grain orientation dependent dissolution [1] even after large amounts of dissolution [2]. Dissolution behavior is dominated by the dissolution of irrational orientations producing high surface roughness caused by significant faceting to low index planes. - The formed terrace-ledge structure was maintained in individual grains after increased dissolution. These observations are consistent with dissolution eventually revealing slow dissolving low index terraces and steps. Further dissolution proceeds most rapidly laterally on the ledge and kink facets. CORROSION MECHANISMS IN AMORPHOUS SOLID SOLUTION ALLOYS: Role(s) of Minor Alloying Elements John R. Scully, University of Virginia Main Campus, DMR 0906663 [1] Dissolved disordered fcc Fe 50 Pd 50 400 s {100} {111} Key result: Dissolution depth linearly dependent on plane normal angle from {100} and {111} 1 2 3 5 4 6 6 4 2 1 3 5 Near {100} ] Behavior after increased dissolution Most dissolved orientations have highest roughness increased surface faceting

[1] Dissolved disordered fcc Fe 50 Pd 50

  • Upload
    heinz

  • View
    22

  • Download
    0

Embed Size (px)

DESCRIPTION

CORROSION MECHANISMS IN AMORPHOUS SOLID SOLUTION ALLOYS: Role(s) of Minor Alloying Elements J ohn R. Scully, University of Virginia Main Campus, DMR 0906663. [1] Dissolved disordered fcc Fe 50 Pd 50. - PowerPoint PPT Presentation

Citation preview

Page 1: [1]   Dissolved disordered fcc Fe 50 Pd 50

Atom scale structure and minor solute exert strong effects on the corrosion properties of ideal solid

solution alloysThe effects of structural (order–disorder transformation, glass relaxation), chemical (solute clusters, minor solute elements) and structural + chemical defects (solute rich and lean nanocrystals in an amorphous solid solution) on corrosion are investigated using model alloys. • Disordered crystalline Fe50Pd50: The disordered structure has strong grain

orientation dependent dissolution [1] even after large amounts of dissolution [2]. Dissolution behavior is dominated by the dissolution of irrational orientations producing high surface roughness caused by significant faceting to low index planes.

- The formed terrace-ledge structure was maintained in individual grains after increased dissolution. These observations are consistent with dissolution eventually revealing slow dissolving low index terraces and steps. Further dissolution proceeds most rapidly laterally on the ledge and kink facets.

CORROSION MECHANISMS IN AMORPHOUS SOLID SOLUTION ALLOYS: Role(s) of Minor Alloying Elements

John R. Scully, University of Virginia Main Campus, DMR 0906663

[1] Dissolved disordered fcc Fe50Pd50

400 s

{100} {111}

Key result: Dissolution depth linearly dependent on plane normal angle from {100} and

{111}

1

2

3

5 4

6

6

42

1

3

5

Near {100}

[2] Behavior after increased dissolution

Most dissolved orientations have

highest roughnessincreased

surface faceting

Page 2: [1]   Dissolved disordered fcc Fe 50 Pd 50

Corrosion Education• 6 high school students (M. Fox, S. Gorsch, L. Scully, D. Harrington, S.

Gorsch, A. Clyman), 3 Undergraduates (H. Bindig, W. McCarthy, A. Nguyen), 3 graduate students (T. Aburada, N. Tailleart D. Horton), and 2 post-doctoral researchers (H. Ha, D. Horton) contributed to this NSF-supported project.

• Graduate & undergraduate courses in corrosion taught both in class and via distance learning (both MSE 7080 and MSE 3080) for Produced-in-Virginia for Engineers that bring engineering education to workers.

• John R. Scully served on National Academy Study on Research Opportunities In Corrosion (ROCSE). (Fall 2010). Corrosion Video distributed

(Title) IIName, Institution, DMR Award#

Spatio-temporal Chaos in Systems of Broken Symmetry

Eberhard Bodenschatz, Cornell University, DMR Award#0072077

Outreach • NanoDays participation with nano-scale corrosion applications at local schools and museums • cKITs (a set of corrosion experiments) purchased from National Association of Corrosion Engineers supplied to local K-12 schools• Materials science and engineering demonstrations and lab tours are given in UVa MSE to foster an interest in the physical sciences and

materials science.

CORROSION MECHANISMS IN AMORPHOUS ALLOYS: CRITICAL COMPOSITIONAL AND STRUCTURAL DEFECTS FOR LOCAL CORROSION

John R. Scully, University of Virginia Main Campus, DMR 0906663

Awards and Honors• Nicole Tailleart, John R. Scully: Inaugural Award Recipients of the Corrosion Journal Best Paper Award, "User-selectable Barrier,

Sacrificial Anode, and Active Corrosion Inhibiting Properties of Al-Co-Ce Alloys for Coating Applications." NACE Inter. Conference, 2010.• UVA's Center for Electrochemical Science and Engineering received the 2009 NACE Distinguished Organization Award• John R. Scully: became the Technical Editor of Corrosion (2012) and received the W.R. Whitney 2012 award from NACE for significant

contributions to corrosion science and the H.H. Uhlig Award, 2009 of the Electrochemical Society for excellence in corrosion research.• Tomohiro Aburada was one of twelve invited students internationally to present at Gordon Research Seminar, New London, NH 2010.• Derek Horton was one of fifteen invited students internationally to present at Gordon Research Seminar, New London, NH 2012.• H. Bindig Nace Top Undergraduate NACE Poster Award 2011 and Runner-up in the 2011 Individual Undergraduate Research and Design

Symposium selected from 1300 graduating UVA engineers

H. Bindig, Runner-up – 2011 Individual Undergraduate

Research and Design Symposium