Description
Tungsten and molybdenum products are manufactured by using either powder metallurgy or by molten route (electron-beam or vacuum arc melting). Powder metallurgical processing has decisive advantages over the other methods and therefore is most widely used. The fine-grained microstructure is easier for further processing and improves the mechanical properties of the final products.
Tungsten and molybdenum sintered products mainly include: Sintered tungsten, molybdenum crucibles, tungsten tube, molybdenum tube target, plate, rod, etc.
Manufacturing Processes of Tungsten and Molybdenum Products
1. Pressing: After screening and homogenization, tungsten and molybdenum powder is pressed into rods and plates of various geometries and dimensions. This takes place using either hydraulic press with steel dies or by isostatic pressing, in which a rubber bag is filled with powder for consolidating into a compact by water or oil pressure acting on all sides.
2. Sintering: This is the following step in the process of tungsten and molybdenum products. Sintering then takes place usually in hydrogen furnaces at temperatures ranges from 1,800℃ to 2,400℃ (2,073K to 2,473 K). The mechanical strength and density increases during the sintering process to reach the properties' necessarity for further processing to semi-finished products.
3. Forging: The sintered tungsten and molybdenum products are then hot worked at temperatures in the range of 1,200℃ to 1,500℃ (1,473 to 1,773 K), using processes such as extrusion, forging or rolling. As the degree of deformation increases the working temperature can be reduced. In this forged and rolled parts, round bars, sheets, foils and ribbons are produced.
4. Reheating and Cooling: Reheating and cooling is the crucial segment in the manufacturing of tungsten and molybdenum sintered products. During sapphire production, Al2O3 (the compound) that is to become the future single crystal is melted in molybdenum and tungsten crucibles. It is in the crapulous process that our pressed-sintered crucibles show their strengths to best effect. They are repeatedly heated to more than 2,000 °C(3,632 °F) and then cooled down again.
Our Company's Advantages
1. We have many years of experience in the field of powder metallurgy, so we can produce tungsten and molybdenum products of particularly high density and purity.
2. We achieve uniform wall and base thicknesses--an important prerequisite in achieving the high level of creep resistance.
3.The surface roughness of our tungsten pressed-sintered crucibles is less than 1 µm. Such crucible is the representative of tungsten and molybdenum sintered products in our company. The sapphire can be extracted from the crucible without difficulty and without damaging the surface of the crucible. For the sapphire producers, this results in fewer complexes and expensive reworking of the surface of the crucible. The cycles run smoothly and deliver high-quality ingots.
4.The smooth surface of our tungsten and molybdenum products is less susceptible to corrosion caused by the aggressive melted sapphire. This increases the service life of them.
Achemetal Furnance Co., Ltd. specializes in producing tungsten and molybdenum sintered products. We adopt high-quality raw materials and annually provide 400 tons high-class tungsten molybdenum products for global customers. The production line includes foil, sheet, plate, and fabricated parts as well as pressed and sintered parts. Above 60% of our products are exported to more than ten countries and areas, such as USA, Germany, Japan, Russia, South Korea, etc. Meanwhile, parts of our products are selected and used by nonferrous metals research institutes.
