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1319 |
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Monday, June 02, 2008, Room 04 11:30 AM Wear Protection 1 Special processes for coatings against wear, improved surface roughness of as sprayed coatings, improved sliding behavior |
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Effect of the structural scale of plasma sprayed alumina coatings on their friction coefficients |
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Hélène Ageorges / University of Limoges,SPCTS , FRANCE Jeoffrey Darut*/ University of Limoges SPCTS, FRANCE Alain Denoirjean/ University of Limoges SPCTS, FRANCE Ghislain Montavon/ University of Limoges SPCTS, FRANCE Pierre Fauchais/ University of Limoges SPCTS, Limoges |
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The objective of this study is to compare the tribological properties of alumina coatings elaborated by Atmospheric Plasma Spraying (APS) with two types of powders. The first one, quite conventional, is made of micrometric particles which medium size is 36 µm and the second one is made of agglomerated nano particles which particles medium size of 20 µm. Various coatings are sprayed, on a AU4G aluminium alloy substrates, under different experimental conditions (H2 vol% in Ar, arc current, powder carrier gas flow rates). The coatings are analyzed by scanning electron microscopy (SEM), energy dispersion probe (EDS) and X-ray diffraction. The friction coefficient is measured and wear tests by linear abrasion in dry condition are achieved. Microhardness measurements are performed applying Vickers indentation. The coatings made with agglomerated nano particles present, as expected, a finer structure and the best wear-abrasion resistance but also less porosity than those obtained with micrometric particles, but the latters exhibit a higher microhardness. |