The uses of molybdenum tubes
The molybdenum tube, with a melting point of 2620 ℃, a low expansion coefficient of 4.8×10⁻⁶/℃, and a high strength that remains at 1600 - 2000 ℃, has become the core heating or supporting component for vacuum sintering furnaces, sapphire crystal growth furnaces, and SiC crystal furnaces. The Φ50 mm guide tube has a service life of over 5 years in the polycrystalline silicon ingot furnace and is also used as a heat treatment fixture for titanium alloys to prevent the contamination of workpieces by iron-based tooling at high temperatures.
In semiconductor and photovoltaic manufacturing, ≥99.95% high-purity molybdenum tubes are used as the crucible sheaths or flow conduits of CZ single crystal furnaces. The inner walls of these tubes are often coated with Si₃N₄ layers to prevent silicon melting erosion. Ion implantation machines use them as plasma transport tubes, which can withstand >10 mA of arsenic ion beam bombardment, ensuring the high purity of silicon materials and process gases.
The aerospace and military industries utilize molybdenum tubes to manufacture the throat liners of rocket nozzles and high-pressure fuel tubes for liquid oxygen/kerosene, with a burst pressure exceeding 100 MPa. After being coated with silicon-containing MoSi₂ or alloyed with Mo-0.5Zr to enhance oxidation resistance and thermal shock resistance, they are also used in the discharge channels of satellite thrusters. In xenon plasma environments, their service life exceeds 10,000 hours.
In the medical and chemical fields, molybdenum tubes are precisely processed into linear accelerator collimator beam-limiting tubes (wall thickness ±0.01 mm, dose error <2%) and Φ1-3 mm radiofrequency ablation catheters; Mo-5Re alloy tubes are used for transporting 700 ℃ fluorine-based salts in molten salt reactors, and the anti-irradiation swelling performance is improved by three times; temperature measurement sleeves for cracking at >1000 ℃ in petroleum are used to replace the deformable Inconel 600.
The manufacturing of molybdenum tubes adopts powder metallurgy + spinning forging (Φ3 - 100 mm, relative density > 99%) or CVD ultra-thin wall (< 0.1 mm, purity > 99.99%);
siliconization/aluminumization coatings can resist oxidation at 1600 ℃ in air, and electrolytic polishing can reduce the roughness of the inner hole to Ra 0.2 μm, meeting the extreme requirements of the synchrotron focusing tube with Ra < 0.05 μm and the first wall cooling pipeline of the tokamak with 14 MeV neutron irradiation.
Mosten Alloy can produce molybdenum sheet, molybdenum block, molybdenum foil, molybdenum rod, molybdenum wire, molybdenum processing workpiece according to customer demand.
