Bulk Analysis of Nickel Based Alloys Using the GDS500A

Importance of the Topic

Nickel-based alloys are critical in high-temperature and corrosive environments such as jet engines, nuclear turbines, and refinery equipment. Reliable chemical composition analysis ensures material performance, safety, and cost efficiency by verifying alloy grade and controlling expensive alloying elements.

Objectives and Study Overview

This study demonstrates the application of glow discharge optical emission spectroscopy (GDOES) using the LECO GDS500A for bulk analysis of nickel alloys. Key goals include verifying alloy composition for incoming inspection, assessing analytical precision and accuracy across various nickel-based standards (e.g., Inconel 718, Waspaloy, Hastelloy B2), and establishing method suitability for QA/QC workflows.

Methodology

The method employs a glow discharge source to uniformly sputter sample surfaces, minimizing effects of metallurgical history. Analyses are conducted off-surface to reduce spectral interferences. Calibration utilizes linear curves derived from certified reference materials over broad concentration ranges, with drift correction via non-certified setup standards. Typical sample preparation includes grinding on a 120-grit zirconium oxide belt.

Used Instrumentation

• LECO GDS500A optical emission spectrometer
• Glow discharge excitation source for uniform sputtering
• LECO BG-30 belt grinder for surface preparation
• Certified reference materials from NIST, BAS, Brammer, MBH, ARMI

Main Results and Discussion

Precision and accuracy were assessed on standards: Inconel 718, Waspaloy, and Hastelloy B2. Results showed average recoveries within 0.5–3.5% relative deviation for major elements (e.g., Cr, Mo, Ni) and trace elements (e.g., B, P, C) with RSDs typically below 2%. Calibration curves for key alloying elements displayed excellent linearity across full concentration ranges (Cr up to 30%, Mo up to 28%, Nb and Ti in relevant grades). Rapid analysis times (70 s for a single burn, 90 s for three replicates) support high-throughput requirements.

Benefits and Practical Applications

• Fast, accurate bulk chemical analysis for incoming inspection and process control
• Reduced matrix interferences due to off-surface excitation
• Wide dynamic range with linear calibrations for major and trace elements
• Efficient drift correction enabling consistent results over long runs
• Cost control through verification of expensive alloying additions

Future Trends and Opportunities

Advancements may include expanded calibration libraries for emerging superalloys, integration with automated sample handling for continuous production monitoring, and enhanced detection limits through optimized spectrometer optics. Coupling GDOES with data analytics could further refine alloy quality prediction and lifecycle management in critical industries.

Conclusion

The LECO GDS500A glow discharge optical emission spectrometer provides a robust method for bulk analysis of nickel-based alloys, delivering rapid, precise, and accurate compositional data. Its broad dynamic range, minimal interferences, and high throughput make it suitable for QA/QC and process control in demanding applications.