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1509 |
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Wednesday, June 04, 2008, Room 08 9:40 AM Pre- and Post-Treatment Thermal sprayed coatings must be regarded as part of a production process, in order to produce superior quality and performance new possibilities in pre- and post-treatment have to be discussed |
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Fast regime ? fluidized bed machining (FR-FBM) of thermally sprayed coatings |
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Massimiliano Barletta / Università di Roma Tor Vergata, Italy Gianluca Rubino*/ Università di Roma Tor Vergata, Dipartimento di Ingegneria Meccanica, Italy Luca Lusvarghi/ Università di Modena e Reggio Emilia, Dipartimento di Ingegneria dei Materiali e dell'Ambiente, Italy Giovanni Bolelli/ Università di Modena e Reggio Emilia, Dipartimento di Ingegneria dei Materiali e dell'Ambiente, Italy Andrea Bassani/ Università di Modena e Reggio Emilia, Dipartimento di Ingegneria dei Materiali e dell'Ambiente, Italy |
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Finishing of thermally sprayed metallic, ceramic and cermet coatings is required in order to meet surface finishing tolerances in most mechanical industry application. Conventional machining is a costly and time-consuming process, difficult to automate. Therefore, this study investigates and develops a new technique highly amenable for automation: Fast Regime - Fluidized Bed Machining (FR-FBM). Atmospheric Plasma Sprayed (APS) TiO2, Cr2O3 and Ni-50Cr and HVOF-sprayed WC-17%Co and Tribaloy-800 coatings, deposited on AISI 1040 steel substrates, were subjected to FR-FBM treatment. The effects of the leading operational parameters, namely, abrasive size, jet pressure and processing time, were evaluated on all coatings by using a two-level full factorial design of experiments. The treated surfaces were observed by SEM and their finishing was evaluated by contact profilometry; their tribological performance was assessed by ball-on-disk dry sliding wear tests. Significant improvement in surface properties of the machined coatings can always be detected, with FR-FBM always able to guarantee the form accuracy and the respect of the closest geometrical tolerances. |