Oxygen in Aluminum and Aluminum Alloys

Importance of the Topic

Oxygen content in aluminum and its alloys critically affects electrical conductivity and product performance. In aluminum wire production, oxide inclusions act as dielectric particles that impair current flow. In thin‐film sputtering applications, oxygen contamination in targets reduces device yield and compromises film quality.

Objectives and Study Overview

This application note presents a semi‐automatic method for determining oxygen in solid aluminum samples using a high‐temperature inert gas fusion analyzer (TC400‐Series). It outlines sample preparation, instrument parameters, calibration procedures and typical analytical results for wires, rods and discs.

Methodology and Instrumentation

The approach relies on inert gas fusion with infrared detection of evolved CO and CO₂ to quantify oxygen. Key steps and components include:

• Sample preparation: machining or abrasion followed by acetone rinse and warm‐air drying to remove surface oxides.
• Reagent addition: one tin pellet, one copper chip and graphite powder placed in a graphite crucible to promote complete reaction.
• Analyzer settings: furnace purge (15 s), outgas (15 s), cool (5 s); power levels set to 6000 W for outgas and 5000 W for analysis; analysis delay 20 s; minimum analysis time 35 s.
• Instrument: LECO TC400‐Series fusion analyzer with graphite crucible, electrode tip and accessories.
• Calibration: steel reference materials (1 g) or rare aluminum‐oxide standards (0.1–0.3 g) analyzed in triplicate for drift correction.

Key Results and Discussion

Typical determinations on aluminum rods and discs yielded oxygen concentrations between 13 and 24 ppm with repeatability (standard deviation) of about 2.8–3.2 ppm. Samples below the instrument range were flagged accordingly. The method demonstrated good precision and sensitivity for low‐level oxygen measurement.

Benefits and Practical Applications

• Quality control in aluminum wire manufacturing: ensuring low oxide content for optimal conductivity.
• Target manufacturing for sputtering: minimizing oxygen to improve thin‐film device yield.
• Fast throughput with semi‐automatic loading and analysis cycles.
• Low detection limits suited for stringent industrial specifications.

Future Trends and Applications

Advances may include fully automated sample handling, integration of laser ablation sampling for non‐destructive analysis, and coupling with advanced data analytics for real‐time process control. Development of certified aluminum oxide reference materials will enhance calibration accuracy.

Conclusion

The described inert gas fusion method on the TC400‐Series analyzer offers a reliable, precise and efficient solution for oxygen determination in aluminum and its alloys. Its application supports critical quality control in both wire and sputtering target industries.

Reference

LECO Corporation. Oxygen in Aluminum and Aluminum Alloys. Inorganic Application Note, Form No. 203‐821‐361, 2009.