Search

DIGITAL LIBRARY: CAMX 2023 | ATLANTA, GA | OCTOBER 30-NOVEMBER 2

Get This Paper

Cold laser ablation as a remediation strategy for contaminated CFRP surfaces

Description

Title: Cold laser ablation as a remediation strategy for contaminated CFRP surfaces

Authors: Joann Hilman, R. Giles Dillingham, Rose Roberts

DOI: 10.33599/nasampe/c.23.0050

Abstract: Undetected surface contamination is a major issue affecting reliable bonding or coating of carbon fiber reinforced polymers (CFRP). The most common remediation method for CFRPs is manual solvent wiping + abrasion. Abrasion is time consuming, difficult to control, physically damaging to the surface plies, and subject to operator-to-operator variability. This has led to the search for faster and more controllable remediation techniques. Laser ablation has gained interest as an automated process with precise parameter control. However, traditional 1064nm nanosecond lasers can cause thermal damage to the resin and carbon fiber, making these lasers nonideal for remediation of CFRP surfaces. Lasers that utilize cold ablation, such as UV and femtosecond lasers, cause less thermal damage and result in more controllable surfaces. This work evaluates and compares two laser systems, a femtosecond laser at 1030nm and a nanosecond laser at 355nm, as potential remediation technology for contaminated CFRP surfaces. Epoxy resin based CFRP samples were protected by peel ply prior to testing. A silicone-based mold release agent diluted in xylene and spun coated onto CFRP surfaces was selected as a model contaminant. Changes to the condition of the CFRP surfaces were tracked in real time using water contact angle. Elemental analysis and surface morphology were studied by x-ray photoelectron spectroscopy and scanning electron microscopy respectively. Mode one fracture toughness was investigated using double cantilever beam tests. Both laser systems were able to effectively remove silicone contamination from the surfaces, however, the amount of contamination removal and amount of carbon fiber exposure were related to the individual ablation process. Mode I adhesive test specimens showed interlaminar failure for the UV laser ablated samples and mixed failure in the adhesive as well as within the resin cap for the femtosecond laser. Both laser systems are a viable method for contamination remediation of CFRP surfaces.

References: L. Hart-Smith, ""Adhesive bonding of composit structures: Progress to date and some remaining challenges,"" Journal of composits technology and research, vol. 24, no. 3, pp. 133-151, 2002. DOI: 10.1520/CTR10566J [2] F. M. Fowkes, ""ATTRACTIVE FORCES AT INTERFACES,"" Ind. Eng. Chem, vol. 56, no. 12, pp. 40-54, 1964. https://doi.org/10.1021/ie50660a008 [3] R. Roberts, J. Fehrman, G. Brown, M. Nichols, I. Smith, B. Buschle and G. Dillingham, ""PLASMA TREATMENT EFFICACY ON UNCLEAN SURFACES FOR BONDING PROCESSES,"" CAMX Conference Proceedings, pp. 764-774, 2022. [4] F. Fischer, S. Kreling, P. Jäschke, M. Frauenhofer, D. Kracht and K. Dilger, ""Laser Surface Pre-Treatment of CFRP for Adhesive,"" The Journal of Adhesion, vol. 88, no. 4-6, pp. 350-363, 2012. https://doi.org/10.1080/00218464.2012.660042 [5] T. Lippert, ""UV Laser Ablation of Polymers: From Structuring to Thin Film Deposition,"" in Laser-Surface Interactions for New Materials Production, Berlin, Springer, 2010, pp. 141-175. DOI: 10.1007/978-3-642-03307-0_7 [6] X. Zhao and Y. C. Shin, ""Coulomb explosion and early plasma generation during femtosecond laser ablation of silicon,"" J. Phys. D: Appl. Phys, vol. 46, no. 33, pp. 1-10, 2013. DOI: 10.1088/0022-3727/46/33/335501 [7] J. L. Hilman and R. G. Dillingham, ""INVESTIGATING HOW PEEL PLY AFFECTS INITIAL CONDITIONS AND AGING OF CARBON FIBER REINFORCED POLYMER SURFACE CHEMISTRY,"" CAMX Conference Proceedings, pp. 131-143, 2022. [8] D. K. OWENS and R. C., ""Estimation of the Surface Free Energy of Polymers,"" JOURNAL OF APPLIED POLYMER SCIENCE, vol. 13, pp. 1741-1747, 1969. https://doi.org/10.1002/app.1969.070130815 [9] C. W. Extrand and S. I. Moon, ""When Sessile Drops Are No Longer Small: Transitions from Spherical to Fully Flattened,"" Langmuir, vol. 26, no. 14, p. 11815–11822, 2010. https://doi.org/10.1021/la1005133 [10] A. Bhandakkar, N. Kumar, R. C. Prasad and S. M. L. Sastry, ""Standard Test ASTM D 5528-01: Method for Mode I Interlaminar Fracture Toughness of Unidirectional Fiber-Reinforced Polymer Matrix Composites 1,"" ASTM, pp. 1-12, 2009. [11] R. J. Morgan and E. T. Mones, ""The cure reactions, network structure, and mechanical response of diaminodiphenyl sulfone-cured tetraglycidyl 4,4′diaminodiphenyl methane epoxies,"" Journal of Applied Polymer Science, vol. 33, pp. 999-1020, 1987. https://doi.org/10.1002/app.1987.070330401

Conference: CAMX 2023

Publication Date: 2023/10/30

SKU: TP23-0000000050

Pages: 13

Price: $26.00

Get This Paper