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2012 |
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Tuesday, May 04, 2010, Hullet Room 9:40 AM Cold Spraying 3 |
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Study of the influence of the substrate temperature on Al coatings deposited by cold spray |
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Silvano Rech / Veneto Nanotech, Italy Simone Vezzù / Civen, Italy Andrea Trentin/ Civen, Italy Eric Irissou/ National Research Council Canada (CNRC-NRC), Canada Jean Gabriel Legoux*/ National Research Council Canada (CNRC-NRC), Canada Mario Guagliano/ Politecnico di Milano, Italy |
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Coldspray deposition is gaining more and more interest in the deposition of thick protective coatings thanks to the low deposition temperature, low residual stress, porosity and oxygen content of deposited coatings. In particular pure aluminium, aluminium alloys and composites could be successfully deposited with thickness up to 1 cm for the protection, the repair and restore of different aluminium components. At this purpose, the study of coating residual stress, adhesion and morphology is of primary importance in order to maximize the deposition efficiency, the coating quality and performances and to identify the window of applicability of coldspray for those applications. This study investigates the influence of the substrate temperature on the deposition efficiency and on the coating properties. Pure Al coatings were deposited on 6061 substrates using CGT Kinetic3000 deposition system. The substrate temperature was ranged between 20 (room temperature) and 400°C and it was kept nearly constant during the deposition while all the other deposition parameters were unchanged. The deposited coatings were quenched in water (within one minute from the deposition) and then characterized. The residual stress were determined by Modified Layer Removal Method, Almen gage method and XRD in order to identify both the mean coating stress and the stress profile through the coating thickness from the surface to the coating-substrate interface. The results coming from different techniques were also compared and discussed. The coating morphology and porosity was investigated by optical and scanning electron microscopy. Finally, microhardness and 4-point bending test were performed in order to determine the coating hardness and the adhesion at the coating-substrate interface. |