Another popular method is based on XRF (X-ray fluorescence) which is now used extensively on PMI (Positive material identification equipment.)

A Niton PMI
Testing parts with an XFR PMI

Fast & Non-destructive chemical analysis of materials

MSL has used XRF analysis technique for positive material identification for many years. MSL is UKAS accredited to ISO 17025 for PMI-XRF analysis using the Niton XL2 Gold XRF.

Our trained users have the experience to work with customers and 3rd party inspectors using the required safety precautions and with appropriate competency.  We use certified reference materials to type match the materials when testing to insure accurate and reliable results.

Materials that can be tested by PMI-XRF

The XRF Chemical analysis method can be used on many metals and alloys.

•           Copper Based Alloys: Brasses, bronze and copper/nickel

•           Iron Based Alloys: Stainless, chromium/molybdenum steels, tool steels and some low alloy steels.

•           Nickel Based Alloys: Inconel, Inco Alloys, Super Alloys

•           Aluminium Alloys

•           Titanium Alloys

•           Exotic Alloys: Tantalum, Zirconium

•           Plating/Coating: Stainless, copper, brass, bronze, chrome, nickel, zinc, zinc/tin

All Types of Parts can be tested

•           Any part that the instruments sensor can make contact with.

•           Finished weld beads and welding rods

•           Rods and wire

•           Bolts, rivets and other fasteners

•           Pump parts such as welds, flanges, blades.

•           Identification of Plating/Coating Materials •           Quick sorting of mixed materials or the verification of traceability quality assurance purposes.

How Does It Work

A key feature of XRF method of chemical analysis is that it is a non-destructive testing method and does not damage or mark the parts that are being tested.  

X-Ray Fluoroscopy (XRF) has an X-ray generator which is used to excite the electrons in the materials being tested and then measures each elements content based on an elemental fluorescent spectrograph. The chemical elements present in the sample are measured and can be compared to the instruments library of material grades/database stored in the instruments memory.

The theory behind XRF chemical analysis

The PMI cannot detect the light alloying elements such as carbon, boron, nitrogen and oxygen, and therefore the instrument cannot differentiate between the various steel grades with different carbon levels. In some cases it uses the other alloy content to distinguish grades, for example, SAE 4130 can be differentiated from SAE 4140 due to the higher manganese range in the SAE 4140.

Elements that can be detected by XRF:

Al, Ti, V, Cr, Mn, Mg, S, P, Fe, Co, Ni, Cu, Si Zn, Gf, Ta, W, Re, Zr, Nb, Mo, Pb, Ag, Sn, Pd. *Instrument does not detect carbon