The XRD phase identification caught trace lepidocrocite that SEM-EDS missed. We adjusted our heat treatment schedule based on the goethite fraction report.
Kasturba Baldev Pandya
Senior Metallurgist, Tata Steel
Three complementary techniques — surface spectroscopy, crystallography, and electrochemistry — deliver a complete picture of long-term corrosion behavior in alloy systems.
Explore test packagesMonochromated Al Kα X-ray photoelectron spectroscopy resolves chemical states of iron, chromium, and nickel in passive films. Detect oxide layer thickness, hydroxide formation, and carbide segregation with 0.1 eV binding energy precision.
Chemical state mappingBragg-Brentano geometry with Rietveld refinement identifies crystalline corrosion products — lepidocrocite, goethite, magnetite, chromium carbides — down to trace levels. Automated ICDD PDF-4+ database matching for multi-phase scales.
Corrosion product crystallographyCyclic potentiodynamic polarization combined with electrochemical impedance spectroscopy measures pitting potential, passive current density, and charge transfer resistance. Data correlates directly with surface analytical results.
Degradation kineticsEngineers and materials scientists share how our surface and corrosion measurements helped them verify long-term structural integrity.
The XRD phase identification caught trace lepidocrocite that SEM-EDS missed. We adjusted our heat treatment schedule based on the goethite fraction report.
Electrochemical impedance spectra from your profiling service matched our field exposure data within 12% deviation. That level of correlation is rare.
XPS surface analysis resolved the chromium oxide thickness on our 316L valves. The 0.1 eV binding energy shift data helped us qualify a new passivation vendor.
We used the combined XPS + electrochemical report to justify a switch from 304 to 2205 duplex in a coastal pipeline project. The passive current density numbers were decisive.
Our four-stage process turns your passivated steel alloy into a quantified structural degradation assessment — no guesswork, just phase data and corrosion kinetics.
You submit a coupon or component. We document geometry, surface finish, and prior exposure history. The sample is cleaned with isopropanol and mounted on a vacuum-compatible holder for XPS and XRD.
We run survey and high-resolution XPS spectra (Al Kα, 1486.6 eV) to map chemical states of Fe, Cr, Ni, O, and C. Simultaneously, a Bragg-Brentano XRD scan (Cu Kα, 2θ 10–90°) identifies crystalline corrosion phases.
Potentiodynamic polarization (scan rate 0.167 mV/s) in deaerated 3.5% NaCl measures pitting potential and passive current density. EIS at OCP from 100 kHz to 10 mHz quantifies charge transfer resistance and coating capacitance.
We cross‑reference XPS chemical state maps with XRD phase fractions and EIS parameters. The final report includes a degradation index, passive film thickness estimate, and recommended mitigation steps.
Definitions and conditions that govern the interpretation of our materials analysis reports, ensuring clarity on measurement boundaries and data applicability.
We define passivated steel alloy as any ferrous alloy that has undergone a controlled oxidation treatment to form a protective surface oxide layer. Our analysis evaluates the stability of this layer under specified environmental conditions, not the bulk mechanical properties of the substrate.
Electrochemical measurements (potentiodynamic polarization, EIS) are performed over a standard 24-hour immersion cycle. Long-term degradation estimates are derived from Tafel extrapolation and charge transfer resistance trends, not from direct long-term exposure. These projections assume a uniform corrosion mechanism and should be validated with field data.
XRD phase identification reports all crystalline phases detected above the instrument detection limit (~1 wt%). For multi-phase scales containing lepidocrocite, goethite, magnetite, and chromium carbides, we provide semi-quantitative phase fractions using Rietveld refinement. Amorphous or nanocrystalline fractions are noted but not quantified unless specifically requested.
Our XPS Surface Analysis Suite achieves a lateral resolution of 100 µm for chemical state mapping. Depth profiling is performed via argon ion sputtering at a calibrated rate of 0.5 nm/min. Reported layer thicknesses are based on sputter yields for standard oxide matrices and may vary for porous or hydrated films.
No. The absence of pitting in electrochemical scans does not guarantee immunity under different environmental conditions. Our pitting potential measurements are valid only for the electrolyte composition, temperature, and scan rate specified in the test protocol. Variations in chloride concentration or pH can shift breakdown potentials significantly.
In our XRD reports, a phase is classified as trace if its estimated weight fraction is below 2%, and minor if between 2% and 10%. These thresholds are based on the statistical reliability of the Rietveld fit. Phases below 1% are flagged as “detected but not quantified” and should be interpreted with caution.