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| Abstract No.: |
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Scheduled at:
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Thursday, June 11, 2020, Hall G1 4:00 PM
Polymer Coatings
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| Title: |
Cold spray coatings of PEEK surface by copper deposition: Interfacial adhesion at high deposition efficiency and bonding strength
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| Authors: |
Rija Raoelison* / Université de Technologie de Belfort-Montbéliard,Laboratoire ICB UMR 6303 Site de Sevenans, LERMPS, France
Rija Nirina Raoelison / Université de Technologie de Belfort-Montbéliard, France
Sophie Costil/ ,
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| Abstract: |
Copper metallization of PEEK is performed by high-pressure cold spraying with high deposition efficiency (DE). Features & bonding strengths are characterized and compared to the case of Cu/Cu combination under the same deposition condition of copper granulometry of 20-40µm, a gas condition of 30bar and 400°C, and a standoff distance of 135mm appropriate to avert undesirable thermal effects on the PEEK surface. The DE of the Cu/Cu combination yields 73% whereas the deposition of the Cu spherical powders onto the PEEK substrate gives a DE of 79% that is slightly higher. These DE values are comparable, but the bonding strengths are very different. The Cu/Cu interface reaches a typical bonding strength of 40MPa while the Cu/PEEK bonding is less resistant with a weak bonding strength of 10MPa. SEM observations of fracture and coated top surfaces exhibit the differences between these two combination cases. The particles are less deformed for the Cu/PEEK case. On the top surface of the coating, they remain nearly spherical with apparent decohesion of deformed particles. In addition, craters due to particle decohesion and rebounds were observed whereas the Cu/Cu case shows more particle flattening but there is also inter-particles decohesion. However, the significant difference appears on the fracture surface of the interface. The Cu/PEEK debonding is characterized by adhesive failure. The coppers that penetrated the PEEK substrate came out leaving craters. In addition, the weakly bonded Cu/Cu particles within the Cu/PEEK interface undergoes rupture. These features explain the low value of the interfacial Cu/PEEK bonding strength. Regarding the Cu/Cu case, the interface breaks by cohesive failure since the fracture surface evidence highly deformed particles with significant flattening. Good metallurgical bonding between the copper particles occurs during the deposition and the greater adhesion strength of Cu/Cu interface is due to more plastic deformation.
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