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Tribo-corrosion maps for engineering materials:some new perspectives

Tribo-corrosion maps for engineering materials:some new perspectives. M.M. Stack Department of Mechanical Engineering University of Strathclyde Glasgow G1 1XJ, UK. Looking for directions…. Need a map…. Ireland Maps.

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Tribo-corrosion maps for engineering materials:some new perspectives

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  1. Tribo-corrosion maps for engineering materials:some new perspectives M.M. Stack Department of Mechanical Engineering University of Strathclyde Glasgow G1 1XJ, UK

  2. Looking for directions…

  3. Need a map…..

  4. Ireland Maps Download these free Ireland maps and then be sure to check out our Irish Coats of Arms Gallery and our Free Tourist Information AgricultureTemperature in JanuarySunshineDensityProvinces

  5. http://www.ireland-information.com/irelandmaps.htm

  6. Map of Ireland http://worldatlas.com/webimage/countrys/europe/ie.htm

  7. Information which a map may provide • Landscape.. • Most convenient route between two locations… • Metrics…

  8. Aims of presenation • Can maps be used to guide materials engineers in materials processes involving tribological and aqueous corrosion processes…. • If so, how can we construct such maps…. • How may they be modified based on the nature of tribological contact and corrosive enviroment..

  9. Tribo-corrosion • Wear due to the combination of tribological and corrosion parameters…

  10. Tribological-velocity, load, temperature, particle size, impact angle, yield strength….

  11. Corrosion-pH, electrochemical potential, Cl-…

  12. Wear map of steels for dry sliding Lim and Ashby, 1987

  13. Wear map for Nimonic 80A vs. Stellite 6 Inman, Rose and Datta, Wear, 2006.

  14. Erosion-oxidation map for steels at elevated temperatures Sundararajan, 1990

  15. 1.6 1.2 0.8 0.4 0.0 -0.4 -0.8 -1.2 -1.6 -2 0 2 4 6 8 10 12 14 16 Corrosion map for Fe in H2O assuming passivation by formation of Fe2O3 O 2 Passivation Corrosion H 2 E, volts (SHE) Immunity Corrosion pH Pourbaix, 1966

  16. Development of tribo-corrosion map in aqueous conditions Sliding wear map Erosion-oxidation map Tribo-corrosion map in aqueous conditions Aqueous - corrosion map

  17. Format • Why use a wear or a corrosion map? • Some useful applications • Development of tribo-corrosion maps-from erosion to micro-abrasion—corrosion

  18. Erosion-corrosion in aqueous conditions Jana and Stack, 2004

  19. Example of surface failed by erosion-corrosion

  20. Polarization curve for Fe in aqueous media p o t e n t i a l , E Transpassive region Passive region E p Active region icrit ipass l o g i

  21. Possible interactions… • Erosion can enhance corrosion i.e. removal of a passive film • Corrosion can inhibit erosion through formation of an adherent ductile film • Corrosion can enhance erosion through dissolution of phases within the material-i.e. as in the case of MMCs

  22. Erosion-corrosion interaction  Kec = Ke + Kc  = {Keo +  Ke} + {Kco+ Kc}   Ke = Keo +  Ke  Kc = Kco+ Kc Kec = Erosion- corrosion rate (measured) Keo = Erosion in the absence of corrosion Kco = Corrosion in absence of erosion Ke = Change in erosion due to corrosion (synergistic effect) Kc = Change in corrosion due to erosion (additive effect) Kc = Total corrosion rate (estimated using Faraday’s law)

  23. Erosion-corrosion rate

  24. Active Region

  25. Passive Region

  26. Erosion-Corrosion Regimes Erosion KC/KE  0.1 Erosion-Corrosion 0.1≤KC/KE  1 Corrosion-Erosion 1 ≤KC/KE 10 Corrosion KC/KE ≥10

  27. Mechanism of wastage …(landscape)...

  28. Erosion-corrosion map for Fe

  29. Fe at pH 7 Pourbaix diagram for Fe (SHE) Erosion-corrosion map for Fe (SCE)

  30. Ni at pH 7 Pourbaix Diagram for Ni (SHE) Erosion-corrosion map for Ni (SCE)

  31. Cu at pH 7 Pourbaix diagram for Cu (SHE) Erosion-corrosion map for Cu (SCE)

  32. Al at pH 7 Pourbaix diagram for Al (SHE) Erosion-corrosion map for Al (SCE)

  33. Comparison between erosion-corrosion regime maps at pH 5 Fe Ni Cu Al

  34. Wastage rate …(metrics)...

  35. Comparison between erosion-corrosion wastage maps at pH 5 Ni Fe Cu Al

  36. Materials selection …(decision on most convenient route...

  37. Comparison between materials performance maps at pH 5

  38. Comparison between materials performance maps at pH 9

  39. Erosion-corrosion of MMC Based materials Abd-El-Badia and Stack, 2006-2007

  40. Erosion-corrosion rig Based on design of Li, Burstein and Hutchings, 1990

  41. Erosion-corrosion mechanisms of MMC based materials

  42. Erosion-corrosion interaction  Kec = Ke + Kc  = {Keo +  Ke} + {Kco+ Kc}   Ke = Keo +  Ke  Kc = Kco+ Kc Kec = Erosion- corrosion rate (measured) Keo = Erosion in the absence of corrosion Kco = Corrosion in absence of erosion Ke = Change in erosion due to corrosion (synergistic effect) Kc = Change in corrosion due to erosion (additive effect) Kc = Total corrosion rate (estimated using Faraday’s law)

  43. Erosion-Corrosion Regimes Erosion KC/KE  0.1 Erosion-Corrosion 0.1≤KC/KE  1 Corrosion-Erosion 1 ≤KC/KE 10 Corrosion KC/KE ≥10

  44. Erosion-Corrosion Regimes •  KC/  KE  0.1 Synergistic 0.1  KC/  KE ≤ 1 Additive- Synergistic  KC/  KE > 1 Additive

  45. 2 ms-1 impact velocity 4 ms-1 impact velocity Erosion-corrosion mechanism maps WC/Co-Cr coating

  46. 2 ms-1 impact velocity 4 ms-1 impact velocity Erosion-corrosion wastage maps WC/Co-Cr coating

  47. 2 ms-1 impact velocity 4 ms-1 impact velocity Erosion-corrosion additive/synergistic effect maps WC/Co-Cr coating

  48. Erosion-corrosion Materials Performance maps 4 ms-1 impact velocity 2 ms-1 impact velocity

  49. Erosion-corrosion of cermets Stack, Antonov and Hussainova, 2006

  50. Erosion-corrosion maps for cermets SEM micrograph of surface of Ni-CR3C2 cermet with 40% wt. Ni. Potential - +500mV. Duration of test – 1 hour. Stack, Antonov and Hussainova, 2006

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