Combining micro-PIXE surface scans with cross-sectional X-ray maps to characterize multilayer structures

Multilayer characterization traditionally involves the direct analysis of the sample cross-section, which is destructive by its nature. Alternatively, an indirect and non-destructive method to obtain a model of the multilayer structures in question is achieved by means of the micro-particle-induced X-ray emission (micro-PIXE) technique. This paper presents a method that utilizes both micro-PIXE surface scan data and electron-induced X-ray maps generated from the specimen cross-section to characterize a multilayer structure, including layer composition, thickness, boundary and density. The proposed approach is demonstrated by characterizing the work material transfer and deposition in a two-layer structure onto the rake face of an uncoated WC-Co tool insert used for machining aluminium. The use of the direct cross-sectional approach allowed an evaluation of the capabilities and limitations of the indirect micro-PIXE approach.