COMPANY SPOTLIGHT
G Series XRF from SciMed provides thickness measurement , elemental analysis , and plating solution analysis .
It quickly and simultaneously measures 5 coating layers , including alloys and ultra-thin films .
NDT ups its game for coating thickness measurement
Neodymium magnets are the most common rare-earth magnet – and the strongest of all permanent magnets , with the ability to lift more than any magnet of equivalent size . They are also ubiquitous , used in a lengthy list of audio equipment , motors and generators , bearings , door closures , pumps , magnetic fasteners – and jewelry .
“ Neo-magnets ” are manufactured from an alloy of neodymium , iron and boron . Because they contain iron , they ’ re plated / coated to prevent corrosion . Most often , that plating is nickel-copper-nickel ( Ni / Cu / Ni ) but zinc , gold , tin , titanium nitride , rubber , PTFE and phosphate passivation are also used . When plated with Ni / Cu / Ni , each layer thickness ranges from a few microns to 10 micron .
X-ray Fluorescence ( XRF ) is the standard method for measuring plated layer thickness in the magnet industry , as elsewhere . XRF instruments use X-ray fluorescence technology to determine the thickness and composition of plated deposits with exceptional accuracy . Measurement is performed by exposing a precisely defined area of the test specimen to x-ray energy . This causes X-ray emission ( fluorescence ) from both coating and substrate , which is detected with an energy-dispersive detector .
Energy resolution and detection efficiency are factors critical to detectors . Energy resolution is the ability to separate two photons that have a small energy difference . Detection efficiency refers to the efficiency of x-ray documentation .
SciMed , a distributor of laboratory and process equipment , represents Bowman XRF systems throughout the U . K . and Ireland . Bowman benchtop XRFs use advanced solid state detector technology , and either a Silicon PIN Detector or a Silicon Drift Detector . By contrast , older XRF instruments use gas-filled proportional counter detectors that , among other things , cannot differentiate between the top and bottom layers of nickel . “ Prop ” counters also cannot distinguish Ni peaks from Cu peaks , unless a secondary filter or a deconvolution algorithm is applied ; these are time-consuming and sensitivitylowering add-ons to the measurement process .
Newer XRF instruments achieve energy resolutions 5 or more times greater than proportional counters , analyze light elements down to Al-13 , and clearly separate Ni and Cu peaks . More importantly , subtle peak structure is revealed , helping distinguish the signals from different nickel layers . The result is a clear differentiation between top and bottom nickel layers . To optimize information from both nickel layers , a primary filter , preferably 0.5mm aluminum , is often used to quelch background noise .
SciMed XRF technicians recently tested Bowman G and L Series benchtop XRFs .
4 MAY 2021 twitter : @ surfaceworldmag