Title: Plasma Surface Preparation for Increased Adhesive Strength of Bonded Fasteners

Authors: Thomas S. Williams, Graham Ray, James Hamtak, Owen Galassini, Chris Galassini, John Elverum

DOI: 10.33599/nasampe/s.21.0432

Abstract: Adhesively bonded fasteners are used extensively in aerospace, automotive and marine applications because they decrease manufacturing complexity while also reducing weight. In this work, plasma surface preparation has been examined as a method to prepare bonded fasteners prior to installation. Successful adhesion requires the generation of a highly clean and active bonding surface. A low temperature plasma device has been used to prepare the bonding surface. A plasma cleaning and activation process has been developed for multiple fastener base materials including parameters such as offset distance, exposure time, gas flow rates, and power level. Plasma will be shown to create a hydrophilic surface with a water contact angle of >5° on epoxy, Polyetherketoneketone (PEKK), Polyetheretherketone (PEEK) and Polyethylenimine (PEI) fasteners. Bond properties were compared with and without plasma activation when using either an epoxy or acrylic adhesive. Data collected using tensile and offset shear tests showed that a point-of-use plasma surface preparation of the fastener prior to bonding was able to increase the maximum bond strength, reduce interfacial adhesion failure and decrease variability. The plasma process will increase bond reliability, decrease touch labor, and reduce scrap/rework/repair (SRR).

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Conference: SAMPE NEXUS 2021

Publication Date: 2021/06/29

SKU: TP21-0000000432

Pages: 15

Price: FREE