WoS İndeksli Yayınlar Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.14901/698

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Citation - WoS: 38
Citation - Scopus: 36
The Effect of Chemical Etching and Nanostructure Additive Epoxy Coating Technique on Adhesion Strength in Aluminum Joints Bonded with Nanostructure Additive Adhesive
(Elsevier Sci Ltd, 2024) Akpinar, Iclal Avinc
In the present study, in order to increase the strength of adhesively bonded joints, the surface of the adherend was chemically etched with an anodizing treatment process at different temperatures and the surface was coated with nanostructure doped epoxy. Additionally, carbon nanostructures were added to the adhesive at different ratios to increase the strength of both the adhesive and the joint. In the study, in order to clean the surfaces of AA2024-T3 aluminum alloy plates and eliminate the oxide layer, the plates were chemically treated with a sodium hydroxide solution. Afterwards, the surfaces of these aluminum alloy plates were chemically etched with an anodizing treatment process at temperatures of 25, 40 and 60 degrees C. The aim here is to create different surface roughness and surface energy on the aluminum alloy surface. Epoxy pre-coating (EPC) was applied to the chemically etched aluminum alloy surfaces. Furthermore, a single-lap joint was produced by adding 0.5 %, 1 % and 2 % carboxylated carbon nanotube (CNT-COOH) by weight to the EPC and adhesive applied to the surfaces and the failure loads of the joints were examined. As a result, when the failure load obtained from the experiments was examined, it was found that chemical etching alone increased the joint strength by 22 % while the chemical etching and EPC application increased it by 46 %, the chemical etching and nanostructure doped EPC application increased it by 61 % and nanostructure addition to the adhesive increased it by 93 %. However, these increases in joint strength vary depending on the duration of the anodizing treatment process and the nano -structure additive ratio. In the chemical analyses performed to interpret these results, surface roughness test, surface contact angle test, X-ray photoelectron spectroscopy (XPS), fourier-transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and images obtained from the failure surfaces were used, respectively.
Citation - WoS: 17
Citation - Scopus: 15
A Study on the Effects of Electrochemical Oxidation and Silane Modification Applied to Fibers in Short Carbon Fiber-Reinforced Structural Adhesives and Adhesive Joints
(Elsevier Sci Ltd, 2025) Akpinar, Iclal Avinc
In this study, electrochemical surface treatment and various silane modifications were applied to fiber structures incorporated into adhesives to enhance the performance of bonded systems. Initially, electrochemical oxidation was performed on the fibers added to the adhesive, increasing the active oxygen groups on their surfaces. Subsequently, silanization was carried out using 3-aminopropyltriethoxysilane (APTES) and glycidoxypropyltrimethoxysilane (GPTMS) as silane agents, improving the surface energy of the fibers. The structural adhesive used in the study was a two-component epoxy adhesive. Composite adhesives were prepared by incorporating carbon fibers treated with electrochemical oxidation and silane modification at weight fractions of 1 %, 2 %, 3 %, and 4 %, and adhesive joints were fabricated using these modified adhesives. According to the results of surface wettability experiments, carbon fibers cleaned with acetone exhibited highly hydrophobic behavior, while fibers subjected to electrochemical oxidation displayed highly hydrophilic behavior. However, subsequent silanization treatments following electrochemical oxidation transformed the surface wettability of the fibers to hydrophilic behavior. Furthermore, the application of electrochemical oxidation to the fibers increased the adhesive's nominal maximum stress value by approximately 126 %, while subsequent silanization treatments following electrochemical oxidation enhanced the nominal maximum stress value by approximately 177 %. These improvements are also supported by the results obtained from shear tests, with the degree of enhancement varying depending on the fiber content added to the adhesive. Changes in the surface functional groups and surface morphologies of the samples were analyzed using X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) imaging.

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Browsing WoS İndeksli Yayınlar Koleksiyonu by Institution Author "Akpinar, Iclal Avinc"