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2651 |
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Wednesday, September 28, 2011, Saal A 9:25 AM Aviation Industry 2 |
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Mechanical property of multi-pass aluminium alloy cold sprayed coatings for repair |
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Silvano Rech* / Veneto Nanotech, Italy Eric Irissou / Nrc-Cnrc, Quebec Canada Andrea Trentin/ Civen, Italy Simone Vezzù/ Civen, Italy |
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The cold spray, for its peculiarity, is becoming increasingly in the reconstruction or repair of damage aluminium alloy components, especially in the aviation industry. Both thin (<0.5mm) and thick (up to centimetres) coatings are necessary in order to achieve dimensional recovery of the components. Contrary to thin, thick coatings can be deposited in single-pass or in multi-pass giving different thermal, mechanical and stress contribution to the components and coatings itself. The thermal input, the amount and the type of residual stresses (compressive or tensile) confer appreciable or depreciable characteristics to the coatings adhesion, the crack propagation and the fatigue resistance. In this study two sets, single and multi-pass aluminium alloy coatings of different thickness are deposited into Al6061 substrate. The metallographic analysis by electronic and optical microscopes, the stress profile measurements by Modified Layer Removing Method (MLRM), the four point flexural test, the cohesion test and the Vickers microhardness are performed; also the multi-pass coatings were characterized by fractografic analysis. Finally the different coating adhesions to substrate are compared by standard ASTM-C633 adhesion test. |