A part fails, or a batch comes in that does not look right, and the question is what it is made of. Computed tomography will show you the shape of every void and crack inside it — and tell you nothing at all about composition. Those are different measurements answering different questions, and choosing between them is usually straightforward once the question is stated properly.
Structure or composition?
The distinction is simple:
- Structure — where the material is, and where it is missing. Porosity, voids, cracks, internal geometry, assembly defects. That is computed tomography.
- Composition — which elements are present, in what proportion, and where on the sample they sit. That is micro X-ray fluorescence.
Neither substitutes for the other. A CT scan of a corroded contact shows the pitting; it cannot tell you whether the plating is the right alloy or whether a contaminant is steel or solder.
How micro-XRF works, briefly
The sample is illuminated with X-rays. Atoms in the material fluoresce, each element emitting at its own characteristic energy, and the detector counts those energies. The result is an elemental fingerprint of whatever the beam is on. Focus that beam down to a small spot and move it across the sample, and you get a map — not just which elements are present, but how they are distributed across a surface.
Nothing is consumed, dissolved or sectioned. The sample goes back into service, back to the customer, or back into the collection.
Where it earns its place
| Question | What micro-XRF gives you |
|---|---|
| Is this the alloy we ordered? | Elemental composition on incoming goods, without preparing a sample |
| How thick is the coating? | Plating and coating thickness, non-destructively |
| What is this contaminant? | Identification of inclusions and foreign particles, and where they sit |
| Is the distribution uniform? | 2D elemental mapping across the surface |
| What is this object made of? | Analysis of irregular, small or irreplaceable objects |
The awkward samples are the point
Bulk analytical methods generally want a prepared, homogeneous, flat sample. A great deal of real work does not look like that: an irregular casting, a tiny inclusion inside a weld, a single component on a populated board, an archaeological object nobody is going to let you cut. Micro-XRF handles non-homogeneous and irregularly shaped samples, and small objects, largely as they are.
That is why it turns up in places as different as electronics failure analysis, incoming quality control, geology and mining, and cultural-heritage conservation — the common thread being that the object matters more than the measurement.
When micro-XRF is the wrong tool
When you need to see inside. Fluorescence comes from at or near the surface. If the question is a void in the middle of a casting or a crack under a joint, that is CT.
When you need light elements in trace amounts. XRF is strong across a wide elemental range, but it is not a universal analytical method, and some questions belong to other techniques entirely.
When the question is mechanical, not chemical. Delamination in a composite, or a disbonded adhesive joint, is not a composition problem — it is a structural one, and often better answered by ultrasound than by either XRF or CT.
Using them together
The most useful pattern is sequential. CT locates the anomaly — here is the inclusion, at this depth, this size. Micro-XRF identifies it — it is this element, so it came from that process step. One answers where, the other what, and a failure investigation usually needs both before anyone can say why.
If you would like to see what your own samples look like on either, get in touch — we can arrange a demonstration in Israel, and we would rather tell you which of the two answers your question than sell you both.