ThePipingMart Blog Grades UNS R05252 Tantalum Alloy – Composition, Properties and Uses

UNS R05252 Tantalum Alloy – Composition, Properties and Uses

UNS R05252

Tantalum UNS R05252, also known as Tantalum 2.5% Tungsten, is a highly corrosion-resistant metal with exceptional strength and durability. It is used in various industries, such as aerospace, chemical processing, and healthcare. This blog post will explore the composition, physical and mechanical properties, heat treatment, welding, and corrosion-resistant properties of Tantalum UNS R05252.

UNS R05252 Composition

Tantalum UNS R05252 consists of 97.5% Tantalum and 2.5% Tungsten. This alloy combination provides Tantalum UNS R05252 with higher strength and improved thermal stability. The alloy’s tungsten content also contributes to its pitting and crevice corrosion resistance.

C O N H Fe Mo Nb Ni Si Ti W Ta
0.010 0.015 0.010 0.0015 0.010 0.020 0.50 0.010 0.005 0.010 2.0 – 3.5 Remainder

UNS R05252 Physical Properties

Tantalum UNS R05252 has a density of 16.6 g/cm³, a high melting point of 2996°C, and a low coefficient of thermal expansion. It exhibits excellent thermal and electrical conductivity, making it suitable for high-temperature applications.

UNS R05252 Mechanical Properties

The mechanical properties of Tantalum UNS R05252 are impressively robust, with a tensile strength of 860 MPa and a yield strength of 760 MPa. Its ductility is also noteworthy, with an elongation at a break of 30%.

Dimension Ultimate Tensile Strength, min, psi (MPa) Yield Strength, min, psi (MPa) (2 % Offset) Elongation, min, %
< 0.125 in. thick 40 000 (276) 30 000 (207) 20
≥0.125 in. thick 40 000 (276) 22 000 (152) 25

UNS R05252 Uses

Tantalum UNS R05252 is primarily utilized in industries requiring high corrosion resistance and mechanical strength. These include but are not limited to aerospace, chemical processing, medical implants, and nuclear reactors.

UNS R05252 Hardness

Tantalum UNS R05252 has a Vickers hardness of 250Hv at 20°C. However, this hardness can be improved using heat treatment processes.

UNS R05252 Heat Treatment

Heat treatment of Tantalum UNS R05252 involves annealing at temperatures between 800-1100°C. This treatment improves the alloy’s strength and ductility while decreasing its hardness. Quenching and ageing can also be used to enhance specific mechanical properties.

UNS R05252 Welding of Tantalum

Welding Tantalum UNS R05252 requires specific procedures due to the alloy’s high melting point and susceptibility to contamination. Welding processes such as electron beam and laser welding are preferred to reduce the risk of contamination while providing high-quality welds.

UNS R05252 Corrosion Resistant

Tantalum UNS R05252 is renowned for its exceptional corrosion-resistant properties. It exhibits excellent resistance to a range of acids, including hydrochloric, nitric, and sulphuric, as well as organic compounds. Additionally, its mechanical strength and low susceptibility to erosion make Tantalum UNS R05252 ideal for use in highly corrosive environments.


Tantalum UNS R05252 is a corrosion-resistant alloy with remarkable strength, ductility, and thermal stability. Its combination of tantalum and tungsten makes it ideal for various applications, from aerospace to medical implants. Understanding the alloy’s composition, physical and mechanical properties, heat treatment, welding procedures, and corrosion-resistant properties is vital to ensure its successful application.

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