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3739 |
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Thursday, May 22, 2014, Hall H1 11:00 AM Automotive Industry 2 |
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Laser texturing surface pre-treatment before PTWA process applied to car engine cylinder bores |
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Sophie Costil* / IRTES-LERMPS / UTBM, France Asmae Mahfoud/ IRTES-LERMPS, UTBM,, France Geoffrey Darut/ IRTES-LERMPS / UTBM, France Amina Lamraoui/ IRTES-LERMPS , UTBM, France Jean-Michel Bordes/ PSA Peugeot Citroën, Centre Technique de Belchamp , France |
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Today, automotive industry has two main objectives: vehicle lightning and energy efficiency. In terms of material, friction parts are studied in order to decrease the energy losses as for the piston liner assembly. For this, thermal spraying and particularly plasma transferred wire arc (PTWA) appears well-adapted to coat cylinder bore. To avoid constraints due to the conventional surface preparation before thermal spraying (high-pressure water jet blasting, mechanical roughening, grit blasting etc&) and to improve the interfacial adhesion, alternatives are often investigated. Among them, laser texturing seems promising. Combining a short-pulse laser with a scanner and multiplying impacts allow to shape the substrate surface to promote the coating mechanical anchorage without weakening the substrate. Regarding the wide range of thermal spray applications, this paper covers such developments specifically in automotive industry. Laser texturing was then considered in order to reach the feasibility of an internal laser treatment of aluminium alloy cylinder. By appropriate selection of laser parameters and spray processes, surface modifications and coating adherence were explored. |