Introduction to Recent Advances in Quality Assessment for Adhesive Bonding Technology

Abstract

The first chapter highlights the relevance of both adhesive bonding technology and in-process quality assessment for mastering twenty-first-century challenges in joining functional and lightweight materials like carbon fibre reinforced polymers. The ongoing developments of the relevant technological and regulatory procedures and frameworks are hereby outlined, following trends for data-driven innovation and standardisation. Advances from monitoring process variables towards the in-depth and objective Extended Non-destructive Testing (ENDT) of material-related features are presented, based on methodological and technological innovation and insights from recent European joint research projects like Horizon 2020s ComBoNDT—“Quality assurance concepts for adhesive bonding of aircraft composite structures by advanced NDT”. Introducing ten heuristic principles for quality assessment in bonding processes, a concept is demonstrated for establishing empirically consolidated sets of quantitative material and process-specific correlations between design-relevant joint features and quality data measured during the manufacture or repair of adhesive joints using ENDT. Each correlation is obtained by systematically introducing disturbances of relevant process features identified by experts and is levelled once by linking findings from standardised mechanical tests with ENDT results obtained for joints that have intentionally been manufactured or repaired in an off-specification way. Subsequent chapters will demonstrate the suitability of the broadly applicable process.

The Influence of MSR-B Mg Alloy Surface Preparation on Bonding Properties

“…Adhesive bonding has been widely described and defined in the literature. According to DIN EN 923 [ 35 , 41 , 42 , 44 , 45 , 46 ], an adhesive is a nonmetallic substance capable of joining materials by surface bonding (adhesion), with the bond possessing adequate internal strength (cohesion). Another popular theory of bonding is the Kinloch theory [ 47 ], which defines an adhesive as a material that, after its application to the material’s surfaces, leads to their bonding and prevents separation.…”

Extended non-destructive testing for inline quality control of cleaning and pre-treatment processes in adhesive bonding of polymer blends

“…Accordingly, there are an increasing number of new and efficient automated solutions available [1], [4][5][6] to support these requirements. As physico-chemical properties of adherend surfaces and, thus, the bond quality that results following an adhesive bonding process are affected by contaminations, procedures for intentionally applying different off-specification process scenarios were developed and their effects on joint strength and fracture surface composition after destructive testing were evaluated [7]. Focusing on different types of contaminations on adherend surfaces like surfactants, model conceptions and numerical models were elaborated to understand related phenomena and to comprehend their effects on interphase properties [8,9].…”

“…Until this day artificial fingerprint contamination or fingerprinted deposits from technical liquids are in the focus of establishing quality assurance procedures for adhesive bonding assembly, e.g. in the European joint research projects FP7-JTI-CleanSky-ICARO, FP7-ENCOMB and Horizon2020-COMBONDT [7,[10][11][12]. Beyond that, greasy or sebaceous [13] natural and latent, i.e.…”