Molybdenum rod forging process
Molybdenum, as a typical high-melting-point metal, exhibits a series of outstanding physical and chemical properties such as low thermal expansion coefficient, high strength, high temperature resistance, corrosion resistance, and excellent electrical and thermal conductivity. These properties make it play a crucial role in many cutting-edge industrial fields including electronics, electric light sources, aerospace, and high-temperature structural components. In recent years, with the rapid development of downstream application technologies, the market has placed higher demands on the specifications and performance of molybdenum rods, driving their development towards larger specifications and higher weights. This trend poses new challenges to the preparation process of large-sized molybdenum rods, especially the key densification forging stage.
Large-sized molybdenum rods are usually made from molybdenum powder and are processed through a series of procedures such as powder loading, cold isostatic pressing, and mid-frequency furnace sintering to produce sintered blanks. During the sintering process, the molybdenum powder particles undergo three stages: bonding, elongation of the sintering neck, and reduction of pores, eventually forming a sintered body with a certain density and strength. However, due to the skin effect of mid-frequency sintering, large-sized sintered blanks are difficult to achieve uniform and dense microstructure. The density distribution in the center and edge of the material is uneven, which cannot directly meet the strict requirements of high-end applications for the homogeneity and stability of the material. Therefore, subsequent plastic processing - mainly the forging process - must be carried out to further achieve densification and uniformity of the material's structure.
After adopting the hydraulic rapid forging process, the average density of the molybdenum rod reached 10.11 g/cm3, which was approximately 99.1% of the theoretical density. Compared to the sintered billet, it increased by 0.25 g/cm3, and it was also higher than the average density of the rods obtained by air hammer forging by 0.11 g/cm3. More importantly, the density values measured at different sampling positions of the hydraulic rapid forged rods were not only higher, but also had a smaller density range. This data fully demonstrates that hydraulic rapid forging has significant advantages in terms of forging toughness and forging uniformity.
After the forging process, the Vickers hardness of the molybdenum rods was significantly improved. The average hardness after hydraulic rapid forging was 203.9 HV1.0, which was 43.5 HV1.0 higher than that of the sintered billet and 9.2 HV1.0 higher than that of the rods forged by air hammer. Similarly, the hardness values at different positions were higher, and the dispersion of hardness distribution was smaller. As an indicator reflecting the local deformation resistance and microstructure state of the material, the hardness once again strongly confirmed the superiority of the hydraulic rapid forging process in achieving uniform and sufficient deformation.
Microscopic observation provides direct evidence for a better understanding of the performance differences. The molybdenum rods that underwent rapid hydraulic forging treatment exhibited typical and uniform fibrous microstructure at both the edges and the core. Compared with the products of air hammer forging， the microstructure of the former is finer and more uniform. This uniform and refined microstructure is the fundamental reason for the material to achieve high density， high hardness and consistent excellent performance. It directly reflects that rapid hydraulic forging can more effectively transfer plastic deformation to the core of the rod， achieving uniform optimization of the overall microstructure.
Under the same deformation conditions, the hydraulic rapid forging process outperforms the traditional air hammer forging in the processing of large-sized molybdenum rods. Its main advantages are as follows: (1) It has better forging penetration and higher forging uniformity; (2) The radial density and hardness of the molybdenum rods produced are higher, and the distribution from the periphery to the center is extremely uniform; (3) It can form a more uniform and fine fibrous processing structure. Therefore, hydraulic rapid forging is a better technical path for achieving stable and efficient industrial production of large-sized and high-performance molybdenum rods.
Molybdenum Sheets are demanded in various parts of the world, such as: USA, Canada, Chile, Brazil, Argentina, Colombia, Germany, France, United Kingdom, Italy, Sweden, Austria, Netherlands, Belgium, Switzerland, Spain, Czech Republic, Poland.
As professional Chinese manufacturer, Mosten Alloy can produce and supply Molybdenum sheet, Molybdenum block, Molybdenum foil, Molybdenum rod, Molybdenum wire, Molybdenum processing workpiece according to customer demand.
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