What is ASTM D7639?
ASTM D7639 is a standard test method for determining the coating weight of zirconium treatments applied to metal substrates. The overall coating weight and zirconium coating weight of a zirconium-containing treatment can be determined using the ASTM D7639 (Standard Test Method for Determination of Zirconium Treatment Weight or Thickness on Metal Substrates by X-Ray Fluorescence) procedure.
What is the Test Procedure and Sample Requirements ASTM D7639?
In ASTM D7639 testing, the peak intensity of the zirconium Ka line (at 0.0786 nm or 15.747
keV) is measured when the test specimen is put in the X-ray beam.
- Specimen size: Test specimens must be flat and free of burrs and deformities in the measuring region.
- Calculation: For ASTM D7639 testing, the weight of the zirconium coating on the test specimen is computed automatically using the calibration curve.
Result and interpretation ASTM D7639 Testing
The process outlined in ASTM D7639 is intended to offer a method for determining the coating weight of zirconium treatments applied to metal substrates. The coating weight of the zirconium treatment in mg/m 2 or mg/ft 2 (or m or nm) is calculated by comparing the intensity to a previously constructed calibration curve or calculation. The exact link between the observed number of counts and the appropriate coating weight (or coating thickness) is determined for each specific combination of substrate and zirconium-containing treatment.
