SAE International

Society of Automotive Engineers International

BTG Labs will be attending the SAE (Society of Automotive Engineers) AMS Aerospace Organization Coatings Committee (AMS G-8)’s annual meeting May 3-5. Dr. Giles Dillingham and Lucas Dillingham will present on “An Integrated Approach to Quantification of Contaminant Effects on Surface Sensitive Processes.” The presentation is based on a collaboration with Lockheed Martin Skunkworks under DARPA support about a new approach at studying surface contaminants. This new approach proposes studying contaminants according to their chemical structure rather than the conventional way which studies the effects of complex contaminant mixtures without identifying and studying individual contaminants. G-8, a branch of SAE, studies adhesive bonding of composites and composes the handbook for bonding composites in aircraft, as well as the publication of the CMH-17 Handbook. SAE strives to standardize language relevant to data generation, testing, and reporting of composites. Below is the abstract for Dr. Dillingham’s presentation.


An Integrated Approach to Quantification of Contaminant Effects on Surface Sensitive Processes ~ Lucas Dillingham, Giles Dillingham / BTG Labs


The detrimental effects of a contaminant are determined by i) the amount of the contaminant in the environment, ii) the affinity of the contaminant for the critical surface, and iii) the compatibility (i.e. solubility) of the contaminant in the adhesive or coating.  The most common approach for evaluating contaminant effects has been to evaluate the effect of a complex blend of multiple contaminants. Because this approach provides no information as to what makes a given contaminant detrimental, it limits our ability to predict the effect of an untested contaminant.    Developing an understanding of the relationship between contaminant structure and effect can lead to more intelligent design of surface preparation processes, more robust adhesive and coating formulations, and more reliable manufacturing processes.

This presentation discusses treating the effects of a complex contaminant mixture as a linear combination of the effects of its constituents. For this paper, they established  levels of various archetype contaminants detrimental to a particular adhesive bonding process. They then established detectability of detrimental levels via various handheld instruments (contact angle measurements, FTIR spectroscopy, and X-ray fluorescence). Using this approach, they demonstrated robust adhesive bonding processes with verifiable and documented surface quality.  This work is addressing a critical step in establishing certification procedures for bonded aircraft assemblies.

Click here to read “A New Approach for the Evaluation of the Effects of Contaminants on Surface Sensitive Processes”