Chemical Characterization of Aerospace Materials – Developments and Challenges: A Comprehensive Survey of Instrumental Techniques

The aerospace industry has made giant strides over the past two decades in addressing several challenges – none more important than that of reduction in fuel consumption. The progress made has been underscored by the development of new materials that not only have the desirable properties, and yet are able to perform reliably in the aggressive environments of the aircraft body and engines.  An important challenge in the development of these next generation materials is the need for comprehensive chemical characterization during the research, manufacturing, and the operational phase of these materials.

Some approaches undertaken by industry in developing novel materials include thermal barrier coatings on substrates, ceramics, composites, and ceramic matrix composites (CMCs). Chemical characterization of these materials, including high accuracy and high precision determination of major compositions, large dimension uniformity assessment of major elements, high sensitivity detection and quantitation of trace, and ultra-trace level impurities and their distributions is essential in achieving the desirable mechanical properties, raw material and product reliability, and useful life cycle. The chemical inertness of these materials presents analytical challenges, making it difficult to incorporate solution-based sample preparation approaches.  Solution-based techniques lose all elemental spatial distribution information and adds burden to achieve high precision of routine measurements. Solid sampling techniques have been developed in addressing these challenges. However, in order to obtain superior figures of merit in analytical methodology, it is important to not only have comprehensive array of instrumentation capabilities, but also to incorporate matrix-matched approaches for method development and routine analyses.  In this study, we present challenges and developments in the chemical characterization of the current state-of-the-art materials and coatings accomplished by using solid sampling approaches.