Pure Molybdenum Tube

Description Of Pure Molybdenum Tube

Pure Molybdenum Tube is a high-performance refractory metal tubular product manufactured from high-purity molybdenum (Mo1 grade, purity ≥99.95%) through powder metallurgy, extrusion, gun-drilling, swaging, drawing, and precision machining processes. It is available in both seamless and welded constructions, depending on size, wall thickness, and application requirements.

Molybdenum offers a unique combination of properties that make it indispensable in high-temperature industrial applications. With a melting point of 2610°C–2620°C — the third-highest among all elements, after tungsten and tantalum — pure molybdenum tubes can withstand continuous operating temperatures up to 1800°C in vacuum or inert gas atmospheres without softening or deformation. The material also offers a density of 10.2 g/cm³, excellent thermal conductivity (~138 W/m·K), a low coefficient of thermal expansion (5.1×10⁻⁶/K), and low vapor pressure and outgassing.

Pure molybdenum tubes are widely used in high-temperature furnaces, thermocouple protection, sapphire crystal growth furnaces, semiconductor manufacturing equipment, glass melting, nuclear energy, and aerospace applications. They can be supplied in bright, polished, pickled, or as-drawn surface conditions, with custom outer diameters, wall thicknesses, and lengths available upon request. TZM and MoLa alloys are also available for applications requiring enhanced creep resistance or higher recrystallization temperatures.

Features Of Pure Molybdenum Tube

• High Purity: Mo ≥ 99.95% (Mo1 grade) ensures minimal contamination in semiconductor, medical, and high-temperature applications.

• High Melting Point: 2610°C–2620°C enables continuous operation at temperatures up to 1800°C in vacuum or inert gas atmospheres.

• Excellent Thermal Conductivity: ~138 W/(m·K) ensures rapid heat transfer and uniform temperature distribution.

• Low Vapor Pressure and Outgassing: Suitable for vacuum and semiconductor applications.

• Good Corrosion Resistance: Resists corrosion from many molten metals, acids, and alkalis.

• Seamless or Welded Construction: Available in seamless or welded designs with smooth inner and outer surfaces.

• Customizable Dimensions: Outer diameter 0.2–400mm, wall thickness 0.1–30mm, length up to 2000mm. Custom sizes available.

• Multiple Grades Available: Mo1, TZM, and MoLa alloys for different high-temperature and creep-resistance requirements.

• Surface Finishes: Bright, polished, pickled, or as-drawn surfaces available.

• Standard Compliance: ASTM B387, GB/T 4188-2017.

Usage Precautions and Limitations Of Pure Molybdenum Tube

• Oxidation at Elevated Temperatures: Molybdenum oxidizes rapidly at temperatures above 500°C in air, forming volatile molybdenum trioxide (MoO₃). Pure molybdenum tubes must be used exclusively in vacuum or inert gas atmospheres (argon, nitrogen, hydrogen) at elevated temperatures.

• Mechanical Handling: Thin-wall tubes are relatively fragile and susceptible to crushing, bending, or kinking. Handle with care during storage, transport, and installation.

• Embrittlement After Use: Molybdenum can become brittle after high-temperature exposure due to recrystallization and grain growth. Used tubes should not be subjected to mechanical stress or reworked.

• Welding and Joining: Molybdenum can be welded using TIG or electron beam welding in inert gas atmospheres, but welding requires specialized techniques due to molybdenum's brittleness.

• Cleaning: Clean tubes with a soft cloth or mild solvent. Avoid abrasive cleaners that could damage the surface or introduce contamination.

• Compatibility Verification: Before ordering, verify that the grade, outer diameter, wall thickness, length, and surface finish are compatible with your specific application requirements.

Specifications Of Pure Molybdenum Tube