Adhesive Joints for Low- and High-Temperature Use: An Overview

Abstract

This work presents a review of several investigations on the topic of adhesive bonding at high and low temperatures. Durability and strength at extreme temperatures have always been a major limitation of adhesives that, given their polymeric nature, exhibit substantial degradation at temperatures where other structural materials (such as metals for example) have minute changes in mechanical properties. However, due to the inherent advantages of bonding, there is a large and continued effort aiming to improve the temperature resistance of adhesive joints, and this effort has been spread among the various topics that are discussed in this review. These topics include adhesive shrinkage and thermal expansion, adhesive properties, joint geometry optimization, and design techniques, among others. The findings of these research efforts have all found use in practical applications, helping to solve complex problems in a variety of high-tech industries where there is a constant need to produce light and strong components that can withstand large temperature gradients. Therefore, the final sections of this work include a discussion on two specific application areas that demonstrate the strict demands that extreme temperature use imposes on adhesive joints and the methods used to improve their performance.

A review on the environmental degradation effects on fatigue behaviour of adhesively bonded joints

“…The mechanical properties of polymer‐based adhesively bonded joints present a strong temperature dependency, especially closely to the adhesive's glass transition temperature ( T g ) 1,3 . At temperatures above T g , the adhesive changes from a rigid and high‐strength material to a weak and more flexible one.…”

“…In general, high‐temperature adhesives presents high T g , whereas adhesives for low‐temperature applications have a low one. Table 1 shows a list of typical glass transition temperatures for different adhesive materials 3 …”

“…Among the main advantages that adhesive bonding have over mechanical fastening methods are a more uniform stress distribution on the bonded area, less weight penalty, a higher fatigue resistance and a longer fatigue life. Other advantages are that they present a good sealing, capacity of joining dissimilar components and potential reductions in life‐cycle maintenance costs 1–5 …”

The Critical Energy Release Rate of Welded Joints Between Fiber-Reinforced Thermoplastics and Metals When Thermal Residual Stress is Considered

“…The influence of thermal stress on joint strength has been discussed for a variety of configurations [11][12][13][14][15][16][17][18]. In case of adhesive bonding, thermal stress can be minimized with selecting appropriate adhesives, adherends and joint geometry [19]. In contrast, when an FRTP and a metal are welded directly, thermal stress due to the temperature gap cannot be avoided.…”

Degradación ambiental y en condiciones adversas de adhesivos estructurales : análisis y consideraciones técnicas para su aplicación industrial

“…Marques et al [36] realizaron una revisión de varias investigaciones sobre el efecto de la temperatura, tanto alta como baja, sobre la unión adhesiva. La durabilidad y la resistencia a temperaturas extremas han sido habitualmente una de las principales limitaciones de los adhesivos que, dada su naturaleza polimérica, presentan una degradación sustancial a temperaturas donde otros materiales estructurales (los metales, por ejemplo), tienen pequeños cambios en las propiedades mecánicas.…”