Experimental assessment of the effect of surfacecondition on aged adhesive joint performance-Reference-Cited by-同舟云学术

Experimental assessment of the effect of surfacecondition on aged adhesive joint performance

Published:2024-04-19 Issue: Volume: Page:
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Author:

Vervaeke Rens¹,Weiland Josef²,Buysschaert Frank¹,Debruyne Stijn¹,Vandepitte Dirk¹,Schiebahn Alexander²,Moens David¹

Affiliation:

1. KU Leuven

2. RWTH Aachen University

Abstract

Industries such as aerospace are very interested in the use of structural adhesives as a joining technique. Compared to riveting, they offer better stress distribution, eliminating stress peaks which can be quite problematic with thin sheet materials. The ability to bond different materials allows for a wider range of material combinations that result in weight reduction. Aluminium and other metals are popular in the aerospace industry, but their reactivity to water molecules compromises the bond strength. This presents problems for manufacturers in predicting and monitoring service life. This study addresses degradation at the interface and the importance of proper surface treatment. Two different adhesive types (epoxy and methylacrylate) and adherent materials (AW 5754 H111 and AISI 1.4301) result in four different sample configurations. Several pretreatments are applied, all using different mechanisms to improve adhesion Drozdziel2022 \cite{Ebnesajjad2015} Marques2020. After surface treatment, the contact angle with de-ionised water is measured, which is directly related to surface energy \cite{Ebnesajjad20151}. The samples are tested for residual lap shear strength after being subjected to an ageing trajectory for one week. Statistical analysis is used to establish a relationship between surface energy and residual lap shear strength. The importance of surface treatment is established, but there is no direct relationship between contact angle and joint durability. Corrosion protection appears to be important, and the adherent material and adhesive type determine the optimum surface treatment.

Publisher

Springer Science and Business Media LLC

Reference12 articles.

1. Yasmina Boutar and Sami Na ïmi and Salah Mezlini and Moez Ben Sik Ali (2016) Effect of surface treatment on the shear strength of aluminium adhesive single-lap joints for automotive applications. International Journal of Adhesion and Adhesives 67: 38-43 https://doi.org/10.1016/j.ijadhadh.2015.12.023, Elsevier Ltd, 6, Aluminium and alloys,Lap-shear,Polyurethane,Surface roughness,Wettability, 01437496, Adhesive joints exhibit very high toughness and good fatigue resistance. This technique is a serious candidate to replace rivets or welding in primary structural components. Nevertheless, there is hesitation on the part of the industry to replace traditional fasteners in primary structural applications, mainly due to the limited understanding of joint performance over the life of structures. In the present research, we focus on the static strength of adhesive bonded aluminium alloys for the automotive industry. So, the aim of this work is to carry out and quantify the various variables affecting the strength of single lap joints, especially the effect of the surface preparation. Aluminium single lap joints (SLJs) were fabricated and tested to assess the adhesive (structural one-component polyurethane adhesive) performance in a joint. We found that the decrease in surface roughness was found to increase the shear strength of single lap joints. Furthermore, it has been possible, qualitatively, to identify the relative sensitivity of the effects of various surface roughnesses on the behaviour of spreading kinetics. Experimental results show that rougher surfaces have less wettability which is in coherent with shear strength tests.

2. Ana C. Marques and Alexandra Mocanu and Nata ša Z. Tomi ć and Sebastian Balos and Elisabeth Stammen and Asa Lundevall and Shoshan T. Abrahami and Roman G ünther and John M.M. de Kok and Sofia Teixeira de Freitas (2020) Review on adhesives and surface treatments for structural applications: Recent developments on sustainability and implementation for metal and composite substrates. Materials 13: 1-43 https://doi.org/10.3390/ma13245590, MDPI AG, 12, Adhesive,Certification,Surface pre-treatments,Sustainability, 24, 19961944, Using adhesives for connection technology has many benefits. It is cost-efficient, fast, and allows homogeneous stress distribution between the bonded surfaces. This paper gives an overview on the current state of knowledge regarding the technologically important area of adhesive materials, as well as on emergent related technologies. It is expected to fill some of the technological gaps between the existing literature and industrial reality, by focusing at opportunities and challenges in the adhesives sector, on sustainable and eco-friendly chemistries that enable bio-derived adhesives, recycling and debonding, as well as giving a brief overview on the surface treatment approaches involved in the adhesive application process, with major focus on metal and polymer matrix composites. Finally, some thoughts on the connection between research and development (R &D) efforts, industry standards and regulatory aspects are given. It contributes to bridge the gap between industry and research institutes/academy. Examples from the aeronautics industry are often used since many technological advances in this industry are innovation precursors for other industries. This paper is mainly addressed to chemists, materials scientists, materials engineers, and decision-makers.

3. Jakub Korta and Andrzej Mlyniec and Tadeusz Uhl (2015) Experimental and numerical study on the effect of humidity-temperature cycling on structural multi-material adhesive joints. Composites Part B: Engineering 79: 621-630 https://doi.org/10.1016/j.compositesb.2015.05.020, Elsevier Ltd, 6, B. Adhesion,B. Environmental degradation,D. Mechanical testing,E. Joints/joining,Multi-material, 13598368, The following paper describes investigations on the impact of harsh environment on shear and tensile strength of multi-material adhesive joints. The samples were made from carbon fiber - epoxy composites, aluminum and two types of advanced steels: abrasion resistant and high-strength. In order to assess the suitability of structural bonding for this sort of applications, it was decided to test two different epoxy-based adhesives, designed for moderate and elevated operating temperatures. The harmful conditions were simulated by means of humidity-temperature cycling tests, according to the SAE standard. The obtained results revealed that even moderately harsh humidity-temperature loads can cause debonding of the joints, even if no external forces are applied. In order to gain insight into this phenomenon, a series of finite element analyses was performed, simulating the exposure of the samples to the chosen environmental conditions. Based on these studies, the temperature expansion coefficient was identified as the crucial factor for the performance of the joints made from dissimilar materials. The results of the described experiments, confirmed by numerical calculations, constitute a guideline for multi-material structural design, supporting this constantly growing branch of modern engineering with a relevant input.

4. G. Viana and M. Costa and M. D. Banea and L. F.M. da Silva (2017) Water diffusion in double cantilever beam adhesive joints. Latin American Journal of Solids and Structures 14: 188-201 https://doi.org/10.1590/1679-78253040, Brazilian Association of Computational Mechanics, Adhesive joints,Diffusion,Double cantilever beam,Hygrothermal ageing,Moisture degradation, 2, 16797825, Structural adhesives are increasingly being used in the aerospace and automotive industries. They allow for light weight vehicles, fuel savings and reduced emissions. However, the environmental degradation of adhesive joints is a major setback in its wide implementation. Moisture degradation of adhesive joints includes plasticization, attacking of the interface, swelling of the adhesive and consequent creation of residual stresses. This may lead to reversible and irreversible damage. In this work double cantilever beam (DCB) specimens using two different adhesives for the automotive industry were subjected to two different ageing environments. They were tested periodically until the toughness of the adhesives stabilized, which means that they were fully degraded. An association was made between the toughness of the adhesive and the amount of water that it had absorbed. This way it was possible to indirectly measure the water uptake in an adhesive joint taking into account the water uptake properties of the adhesives studied, which had been determined in another study. It was found that diffusion of water into the studied adhesive joints was faster than diffusion through the bulk adhesive alone. A model that takes into account diffusion through the interface between the adhesive and the adherends was proposed.

5. L F M Silva and Chiaki Sato (2013) Design of Adhesive Joints Under Humid Conditions. 25, 11, 978-3-642-37613-9, 10.1007/978-3-642-37614-6