Adhesive bonding materials, characterization

Applications of Ion Beam Methods to Characterization of Adhesive Bonding Materials... 

Ion Beam Methods to Characterize Adhesive Bonding Materials 123... 

The outline of this chapter is as follows. The spectroscopic techniques that can be used for surface of interface characterization of adhesively bonded materials are listed in Table 1. The most popular techniques are then discussed briefly in terms of the type of information they provide and where they can be applied. Their limitations are also described briefly. Since just a handful of techniques are used on a regular basis, notably XPS, AES, SIMS, FTIR, and Raman spectroscopy, only these techniques will be discussed in detail. Recent and ongoing instrumental developments are described and specific applications of each of these techniques are presented and discussed. Finally, a bibliography containing many references to textbooks and important artieles is given. 

W. L. Baun, Applications of ion beaih methods to characterization of adhesive bonding materials, in Interfacial Applications of Surf ace Analysis (L. A. Casper and C. J. Powell, eds.), pp. 121-141, American Chemical Society, Washington (1982). 

Adhesive wear is characterized by transfer of material from one material to another during sliding as a result of the adhesive forces at the contact points. The transferred material accumulates until the surface forces cause wear particles to form 50). Because the rate at which polymeric material transfers depends on the bonding at the contact point — Coulombic and van der Waals — adhesive wear is usually small compared... 

Ion beams provide useful information either as a diagnostic tool or as a precision etching method in. adhesive bonding research. The combination of SIMS with complementary methods such as ISS or AF.S provides a powerful tool for elemental end limited structural characterization of metals, alloys and adhesives. The results shown here indicate that surface chemistry (and interface chemistry) can be decidedly different from bulk chemistry. Often it is this chemistry which governs the quality and durability of an adhesive bond. These same surface techniques also allow an analysis of the locus of failure of bonded materials which fail in service or test. 

Independent of the chemical structure, industrially available adhesives are characterized by the formation of strong adhesive bonds on the respectively pretreated surfaces of the materials described. This results in the criteria for adhesive selection described in Chapter 8. 

The IR and microwave, or dielectric, curing adhesives processes have not been well characterized. IR can either dry solvent or water, or it may cause cure microwave or dielectric heat is frequently used to soften thermoplastics which bond. Materials in current use with this type of... 

Adhesion is an interfacial phenomenon that occurs at the interfaces of adherends and adhesives. This is the fact underlying the macroscopic process of joining parts using adhesives. An understanding of the forces that develop at the interfaces is helpful in the selection of the right adhesive, proper surface treatment of adherends, and effective and economical processes to form bonds. This chapter is devoted to the discussion of the thermodynamic principles and the work of adhesion that quantitatively characterize the surfaces of materials. Laboratory techniques for surface characterization have been described which allow an understanding of the chemical and physical properties of material surfaces. 

W. E. Woodmansee, Through-transmission ultrasonic attenuation measurements on adhesively-bonded structures, in Ultrasonic Materials Characterization, NBS SP 596, pp. 425-432, Proc. 1st International Symposium, Gaitherburg, MD (June 7-9, 1978). 

D. K. McNamara is a scientist at Martin Marietta Laboratories. He joined the Laboratories in 1973, having previously worked at Mound Laboratory and Brookhaven National Laboratory in instrumentation and vacuum system design. His interest in structural characterization has involved research into such diverse materials as silicon nitride, metal- and polymer-based composites, and metal carbides. He has studied extensively the role of surface preparations in adhesive bonding, from both theoretical and practical standpoints. 

All adhesives are polymers, and they are used in many ways, for example in composites, automotive tire cords, ply yood, tapes and labels. A particularly demanding application is the cementing of metal joints in military aircraft with polymers such as epoxy resins. The interfaces in such materials must be characterized to determine the strength of the adhesive bond and the relation of such properties as peel strength with... 

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