Techniques

SEM Image of Plating LayersDot Mapping for PlatingSEM: Scanning electron microscopy combines high magnifications exceptional depth of field to allow detailed microstructural examination of most materials. Sample preparation is quick and simple and the images obtained can have immense diagnostic value. Fracture surface topography, 3-D particulate morphology and surface finish can be qualitatively assessed by visual inspection.
EDXA: Within the SEM, points on the sample can be targeted with an x-ray beam and their elemental composition determined quantitatively. By scanning many such points, elemental ‘maps’ of a surface can be produced to identify where individual elements are concentrated within the sample. With careful use, the composition of the constituent microstructural parts of a sample, e.g. grains, domains or particles, can be determined.

EDXA-maps of W, Ti + Co, cutting wheel sample
OPTICAL MICROSCOPY: although requiring greater sample preparation than SEM, optical micrography has the extra dimension of colour to add further diagnostic capabilites. This traditional but powerful technique is an excellent complement to SEM and has particular uses in determining e.g. coating thicknesses, corrosion profiles and grain structure.

Optical micrograph of a paint film thickness
OTHER TECHNIQUES: AME also has access to other powerful diagnostic techniques including;
1. XRD: X-ray diffraction allows compounds and crystal structures to be determined rather than elemental compositions. Can be performed on powder or flat samples. Particularly powerful when used alongside EDXA.
2. Petrography: examination of thin sections of particularly ceramic, geological or cementitious materials under polarised light can provide striking images with diagnostic value
3. Micro-hardness testing: using diamond indenters, the hardness of a huge range of materials can be determined; variations in hardness in material can help diagnose many problems
4. Mechanical testing: tensile, bending and fatigue testing can all be performed at competitive rates and included in the same report as micro structural findings.