Quantitative Depth Profile (QDP) Analysis of Elastomer Bonded Steel Sandwich

Significance of the Topic

The accurate determination of coating and bonding layer thickness is critical for quality control and material performance assessment in industrial and research settings.

Objectives and Study Overview

This study demonstrates the use of the LECO GDS850A glow discharge atomic emission spectrometer to quantify the thickness and composition of an elastomer layer bonded between two steel sheets. Comparative measurements using optical image analysis are also presented to validate the method.

Methodology and Instrumentation

The elastomer-steel sandwich was prepared by grinding one side to expose a thin steel overlayer. Depth profiling proceeded from the top steel surface through the elastomer to the bottom steel using the following setup:

• LECO GDS850A spectrometer with a 4 mm RF glow discharge lamp
• Optional RF Sample Cooling Kit to prevent thermal artifacts, preferential sputtering, and polymer softening
• PAX-it Basic Measurement Module on a LECO Image Analyzer for optical thickness comparison

Sputtering and emission data were collected continuously, with depth calibration based on the criterion of 84 % of the maximum matrix element signal.

Main Results and Discussion

Quantitative depth profiles revealed an average elastomer thickness of 31.4 µm and a total sandwich thickness of approximately 114 µm. Replicate analyses showed high reproducibility (RSD ~4.8 % for elastomer thickness). Elemental distribution plots indicated clear transitions between steel and elastomer layers. Optical measurements at 50× and 500× magnification confirmed the GD-AES results, demonstrating agreement between spectroscopic and imaging techniques.

Benefits and Practical Applications

• Non-destructive to remaining layers beyond the analysis region
• High precision and reproducibility for process control
• Capability to characterize layer composition as well as thickness
• Suitable for R&D and routine QA/QC in coatings, adhesives, and surface treatments

Future Trends and Potential Applications

Advances in glow discharge sources and detector sensitivity will extend quantitative depth profiling to thinner films and more complex multilayer systems. Integration with automated image analysis and machine learning could enhance throughput and interpretive accuracy. Emerging applications include nanocoatings, advanced composites, and failure analysis of bonded structures.

Conclusion

The LECO GDS850A provides a robust and reproducible approach for quantitative depth profiling of elastomer-bonded steel assemblies. Its results align closely with optical image analysis, offering a versatile tool for both research and industrial quality assurance.

References

No external literature references were provided in the source document.