Corrosion Resistance Of Tantalum To Water, Aqueous Solutions And Non-metals

Tantal - Element Information and Properties

Tantal is selected for applications where high corrosion resistance is required. Tantal is frequently compared with noble metals because it displays resistance towards a broad range of chemical substances. Thermodynamically, tantalum is classified as a base metal; it forms stable compounds with many elements. When exposed to air, tantalum develops a dense oxide layer (Ta2O5) that protects the substrate. Consequently, tantalum is regarded as corrosion resistant.

Tantal vs Hydrogen

Tantal (Ta) has a melting point of 3017 °C, exhibits high corrosion resistance and possesses considerable ductility at room temperature. Pure Ta undergoes a transition from ductile to brittle at temperatures below –269 °C in both its welded and unwelded states.

Tantalum is the most corrosion-resistant metal in current use. The naturally occurring oxide layer on tantalum accounts for its performance in aggressive media. It shows resistance towards both sulphuric acid and hydrochloric acid. It is inert in the presence of practically all organic and inorganic compounds. Tantalum’s corrosion resistance is equivalent to that of glass, given that neither material is suitable for use in hydrofluoric acid or strong hot alkali solutions.

Tantalum remains inert in sulphuric and hydrochloric acids of concentrations below the specified limits at temperatures under 150 °C. Corrosion effects are insignificant up to 205 °C, and tantalum has been applied at temperatures as high as 260 °C.

Tantalum is not affected by nitric acid at concentrations up to 98% and temperatures of at least 100 °C, thereby proving inert in many corrosive environments.

The material is resistant to aqueous ammonia solutions. If tantalum is chemically attacked, hydrogen penetrates its metal lattice and the material becomes brittle. The corrosion resistance of tantalum gradually decreases with increasing temperature.

Tantalum is inert when in contact with many solutions. However, when exposed to mixed solutions, its corrosion resistance can be adversely affected, even if it is resistant to the individual components.

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Conclusion

Thank you for reading this article. We hope that the information assists in clarifying the properties of tantalum. For further details on tantalum and other refractory metals and alloys, please consult Stanford Advanced Materials (SAM) for additional information.

Stanford Advanced Materials (SAM) is a global supplier of tantalum products and has more than 20 years’ experience in the manufacture and sale of tantalum products. The company supplies tantalum metals that meet the research and production specifications of clients. We believe that SAM will be an appropriate supplier and business partner.