The Importance of X-Ray Diffraction in the Non-Destructive Characterisation of High-Strength Aluminium Alloys

Abstract

X-ray diffraction is a long-established technique for the nondestructive characterisation of crystalline and non-crystalline materials [1–3] and, as such, might appear to lack the glamour and immediacy of newly-developed instrumentation. However, this would belie the major advances that have been made in the technique with the introduction of rapid response detectors, intense tunable synchrotron sources, and, most importantly for the majority of users, the incorporation of computers into both data collection and data processing. These developments have resulted in what can only be described as a minor revolution since modern computer-controlled X-ray diffraction equipment can now provide, non-destructively and quickly, most of the basic structural information that is essential for materials characterisation. This paper will present the types of information that can be extracted from the technique, using as examples some of the high-strength aluminium alloys currently being used, or being considered for use, in the aerospace industry. Whilst the paper will limit itself to X-ray diffraction, it must be recognised that no one technique can provide all the necessary information in the nondestructive characterisation of materials and that full use must be made of any other technique that can complement X-ray diffraction.