Title: Additively Manufactured Tooling for Producing Elliptical Dish Composite Structures using Autoclave Curing

Authors: Khalid Aldhahri, Donald Klosterman, Henry D. Young

DOI: 10.33599/nasampe/s.25.0147

Abstract: Elliptical dish structures are used in a variety of applications, especially in aerospace. The best way to manufacture this structure is using fiberglass reinforced polymer matrix composite materials. Composite materials offer different advantages to create an elliptical dish, such as its light weight, high strength, and improved radio frequency (RF) efficiency. An elliptical dish structure is necessary for RF applications because it can focus and direct signals with high precision, improving signal strength and clarity. Further, proper material selection is essential before manufacturing the finished product, so that it can provide the required factors to achieve these advantages. First, a mold is needed to fabricate and lay-up the fiberglass/polymer materials that will be consolidated, typically in an autoclave. The typical mold-making approach involves computer numerical control (CNC) machining, which is time-consuming, expensive, and requires skilled labor. Additive manufacturing (AM) offers the advantage of creating rapid prototype tooling at a lower cost and less time, making it particularly beneficial for low-batch productions. Fiberglass with polycarbonate and carbon fiber reinforced PA6 (nylon 6) were two types of filament material used in this work to 3D print molds with approximate dimensions 25 cm diameter x 8.5 cm high. Three different infill densities were used to study the effect of mold density on dimensional change during autoclave curing. The 3D printed tool was then used to manufacture the finished composite of elliptical dish structures. Details of the prepreg layup process, vacuum bagging, and cure cycle will be discussed. The final composite part was evaluated for surface finish and structural integrity, while the tool was evaluated for shrinkage / compaction during cure.

References: 1. R.G. Dillingham, B.R. Oakley, Surface Energy and Adhesion in Composite-Composite Adhesive Bonds Journal of Adhesion 82 (4) 407-426, 2006. 2. F.J. Boerio, B. Roby, R.G. Dillingham, R.H. Bossi, R.L. Crane, Effect of Grit-Blasting on the Surface Energy of Graphite/Epoxy Composites, Journal of Adhesion 82 (1) 19-37, 2006. 3. R. L. Crane, Giles Dillingham, Composite Bond Inspection Journal of Materials Science 43 (20) 6682-6694 (2008). 4. F.J. Boerio, B. Roby, R.G. Dillingham, R.H. Bossi, Effect of Surface Engineering Processes on the Surface Properties and Adhesive Bonding of Graphite/Epoxy Composites Proc. 39th International SAMPE Technical Conference, Cincinnati, OH, Oct 29 - Nov 1, 2007. 5. M.N. Charalambides, R. Hardouin, A.J. Kinloch, F.L. Matthews, Adhesively-bonded repairs to fibre-composite materials I: experimental, Composites Part A: Applied Science and Manufacturing. v 29, n 11. 1998, p 1371-1381. 6. J.W. Chin, J.P. Wightman, Surface characterization and adhesive bonding of toughened bismaleimide composites, Composites Part A: Applied Science and Manufacturing 27(6) 1996, pp. 419-428. 7. G. Dillingham and B.R. Oakley, Development of Quantitative Tools for the Assessment of Bond Surface Preparation Quality, Proc. 30th Annual Meeting of the Adhesion Society, The Adhesion Society, Inc., A. Jagota, ed., The Adhesion Society, Blacksburg, VA, 2007. 8. F.J. Boerio, B. Roby, R.G. Dillingham, R.H. Bossi, R.L. Crane, Effect of Grit-Blasting on the Surface Energy of Graphite/Epoxy Composites, Journal of Adhesion 82 (1) 19-37, 2006. 9. M. Strobel, S.M. Kirk, L. Heinzen, E. Mischke, C.S. Lyons, J. Endle, D. Poirier, G. Dillingham, Contact angle measurements on oxidized polymer surfaces containing watersoluble species Journal of Adhesion Science and Technology 29, 1483-1508 2015. 10. A.D. Gilpin, B.R. Oakley, R.G. Dillingham, Water contact angle as a quantitative measure of total polyethylene surface energy, Journal of Adhesion Science and Technology 2015; 29: 890-895. 11. D.L. Allara, A. Baca and C. A Pryde, Distortions of Band Shapes in External Reflection Infrared Spectra of Thin Polymer Films on Metal Substrates, Macromolecules 11, 1215 (1978). 12. Characterization of Metal and Polmer Surfaces, ed. by L.H. Less, Vol. 2, Academic Press, New York, 1977, p. 153.

Conference: SAMPE 2025

Publication Date: 2025/05/19

SKU: TP25-0000000147

Pages: 10

Price: $20.00