Strength of Joints with “Hi-Lok” Fasteners in Aircraft Safety Considerations

This paper reports on the results of strength tests of single-lap joints used in the aerospace industry with “Hi-Lok” fastener. The samples subjected to testing were made of EN-AW 2024 aluminium alloy and carbon composite. A part of the samples was additionally sealed with the use of Naftoseal MC-780 Class C sealant. The application of the MC-780 Class C sealant boosts the strength of a single lap joint of EN-AW 2024 T3 Al alloy and carbon composite. The strength test results were complemented with the analysis of selected 2D and 3D surface roughness parameters, and isometric images of the analysed surfaces. Additional information on the specimen surface quality was provided with photographic images taken with Keyence VHX-5000 microscope at x300 magnification. In the conclusion section of this paper, the study is summarised and its key findings are listed.