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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 M.M. Stack Department of Mechanical Engineering University of Strathclyde Glasgow G1 1XJ, UK
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
Map of Ireland http://worldatlas.com/webimage/countrys/europe/ie.htm
Information which a map may provide • Landscape.. • Most convenient route between two locations… • Metrics…
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..
Tribo-corrosion • Wear due to the combination of tribological and corrosion parameters…
Tribological-velocity, load, temperature, particle size, impact angle, yield strength….
Wear map of steels for dry sliding Lim and Ashby, 1987
Wear map for Nimonic 80A vs. Stellite 6 Inman, Rose and Datta, Wear, 2006.
Erosion-oxidation map for steels at elevated temperatures Sundararajan, 1990
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
Development of tribo-corrosion map in aqueous conditions Sliding wear map Erosion-oxidation map Tribo-corrosion map in aqueous conditions Aqueous - corrosion map
Format • Why use a wear or a corrosion map? • Some useful applications • Development of tribo-corrosion maps-from erosion to micro-abrasion—corrosion
Erosion-corrosion in aqueous conditions Jana and Stack, 2004
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
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
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)
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
Fe at pH 7 Pourbaix diagram for Fe (SHE) Erosion-corrosion map for Fe (SCE)
Ni at pH 7 Pourbaix Diagram for Ni (SHE) Erosion-corrosion map for Ni (SCE)
Cu at pH 7 Pourbaix diagram for Cu (SHE) Erosion-corrosion map for Cu (SCE)
Al at pH 7 Pourbaix diagram for Al (SHE) Erosion-corrosion map for Al (SCE)
Comparison between erosion-corrosion regime maps at pH 5 Fe Ni Cu Al
Comparison between erosion-corrosion wastage maps at pH 5 Ni Fe Cu Al
Erosion-corrosion of MMC Based materials Abd-El-Badia and Stack, 2006-2007
Erosion-corrosion rig Based on design of Li, Burstein and Hutchings, 1990
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)
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
Erosion-Corrosion Regimes • KC/ KE 0.1 Synergistic 0.1 KC/ KE ≤ 1 Additive- Synergistic KC/ KE > 1 Additive
2 ms-1 impact velocity 4 ms-1 impact velocity Erosion-corrosion mechanism maps WC/Co-Cr coating
2 ms-1 impact velocity 4 ms-1 impact velocity Erosion-corrosion wastage maps WC/Co-Cr coating
2 ms-1 impact velocity 4 ms-1 impact velocity Erosion-corrosion additive/synergistic effect maps WC/Co-Cr coating
Erosion-corrosion Materials Performance maps 4 ms-1 impact velocity 2 ms-1 impact velocity
Erosion-corrosion of cermets Stack, Antonov and Hussainova, 2006
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