Miklós Berczeli

This study is about laser-induced surface activated DC01 and S235 mild steels, which are bonded with an anaerobic acrylic adhesive (Loctite 270) and a cyanoacrylate adhesive (Loctite 496). A fiber laser was used with 50–100% power, 20–200 kHz pulse frequencies, and scanning speeds were 500–2000 mm/s. Wettability was measured by water contact angle (WCA), and the joint performance was examined through single-lap shear tests. Both untreated steels showed hydrophobic behaviour (DC01: 72.9°, S235: 89.8°), which resulted in low shear strengths: 0.29 kN (DC01, acrylic), 2.03 kN (DC01, cyanoacrylate), 0.57 kN (S235, acrylic), and 0.06 kN (S235, cyanoacrylate). After laser treatment, the WCA was under 5° in most cases, showes complete wetting. This change was reflected in a significant increase in strength. In the case of DC01, the acrylic adhesive achieved 2.9 kN (≈10×) and the cy­anoacrylate achieved 5.6 kN (≈2.5×). In the case of S235, the acrylic adhesive achieved 3.9 kN (≈7×), while the cyanoacrylate increased from 0.06 to 6.1 kN (≈100×). Based ont he results the laser activation can create a clean, high­ly hydrophilic surface. It increases the adhesion of both adhesive systems. Al­though the two steels responded differently to the treatment, in all cases the reduction in the rim angle was closely related to the increased bond strength.

A ragasztott kötések a modern ipari alkalmazások és mérnöki megoldások alapvető technológiai elemei, amelyek alkalmazása kiterjed az autóipar, a repüléstechnika, a mikroelektronika valamint számos más területre. Annak ellenére, hogy az adhéziót meghatározó folyamatok régóta a ragasztástechnológiai kutatások középpontjában állnak, továbbra sincs egyetértés a tudományos közösségekben, hogy melyek azok a kölcsönhatások, folyamatok és tényezők, amelyek legnagyobb mértékben befolyásolják a ragasztott kötések adhézióját. Az adhéziós kapcsolatok mechanizmusainak pontos feltárása nemcsak elméleti jelentőséggel bír, hanem alapvetően meghatározza a kötéstechnológiák ipari alkalmazhatóságát és megbízhatóságát is. A jelen kutatásunk célja, hogy rendszerszintű megközelítéssel vizsgáljuk a ragasztott kötések adhézióját befolyásoló tényezőket. Az irodalomkutatásunk az alapvető adhéziós mechanizmusok, például a mechanikai kapcsolódás, a felületi diffúzió, a kémiai kötések, valamint a nedvesítési tényezők együttes hatására fókuszál. A későbbi, jelen irodalomkutatás alapján meghatározott ragasztástechnológiai kísérleteinkkel célunk, hogy lehetőséget kínáljunk az adhéziós mechanizmusok jobb megértésére és a ragasztástechnológia célzott optimalizálására.

The significance of bonding technology for modern vehicle structural materials is increasingly acknowledged, driven by the adoption of new materials to reduce weight. This is important not only for quality and economic reasons but to address e...

The use and significance of adhesives in various industries are explored, highlighting the growth of the adhesive market and the crucial role of time in adhesive bonding. The composition of adhesives, particularly polyurethane adhesives (PUR),...

This study explores the tensile strength of adhesive joints in steel, focusing on the influence of heat treatment and diverse surface modifications. Results indicate a notable relationship between annealing temperature and tensile strength, with the most favorable outcomes identified at 90 min and 165 °C. Particularly, surfaces treated through turning, sandblasting, and plasma treatment (type C) consistently outperformed other methods. A standout revelation emerged from the turned, sandblasted, and plasma-treated surface (C), showcasing an exceptional tensile strength of 69.06 MPa. Load-holding tests underscored its resilience under diverse load conditions. Surface analyses, including roughness measurements, wetting characteristics, and Scanning Electron Microscope imaging, provided valuable insights into structural transformations induced by different treatments. Chemical composition examinations unveiled significant alterations post-plasma treatment, impacting surface chemistry and contributing to an outstanding tensile strength of 67.63 MPa. In essence, this research offers a glimpse into the nuanced factors influencing adhesive joint strength in steel. The turned, sandblasted, and plasma-treated surface emerges as a promising avenue, sparking further curiosity into the underlying mechanisms propelling superior tensile strength in adhesive joints.

The development of bonding technology and coating technologies require the use of modern materials and topologies for the demanding effect and modification of their wetting properties. For the industry, a process modification process that can be integrated into a process is the atmospheric pressure of air operation plasma surface treatment. This can be classified and evaluated based on the wettability, which has a significant impact on the adhesive force. The aim is to improve the wetting properties and to find the relationship between plasma treatment parameters, wetting, and adhesion. High Impact PolyStyrene (HIPS) was used as an experimental material, and then the plasma treatment can be treated with various adjustable parameters. The effect of plasma parameters on surface roughness, wetting contact angle, and using Fowkes theory of the surface energy have been investigated. Seven different plasma jet treatment distances were tested, combined with 5 scan speeds. Samples with the best plasma parameters were prepared from 25 mm × 25 mm overlapping adhesive joints using acrylic/cyanoacrylate. The possibility of creating a completely hydrophilic surface was achieved, where the untreated wetting edge angle decreased from 88.2° to 0° for distilled water and from 62.7° to 0° in the case of ethylene glycol. The bonding strength of High Impact PolyStyrene was increased by plasma treatment by 297%.