Research On Rolling Technology, Microstructure And Properties Of La-Mo Alloy Plate

Rare earth molybdenum plate not only has good high-temperature strength and creep resistance performance,but also has excellent general mechanical properties prior to Si-Al-K alloy mixed with Mo and TZM after high-temperature annealing.The main applications of Molybdenum plates are molybdenum wafer used in SCR,tube insulation shielding materials,spacecraft skins,guide plates,high-temperature sintering boat, plates and high-temperature radiation heat shield,etc.It has been widely used in the spaceflight,national defense,atomic energy industrial and civilian aspects,the consumption of which is about 800t per year.In this paper,three rolling processes of La-Mo alloy plate were studied,with the content of pure molybdenum and La₂O₃ is 0.26wt%,0.54wt%and 0.97wt%, respectively.Microstructures and mechanical properties of the material were measured by optical microscope,scanning electron microscopy(SEM) and universal testing machine.The effects of RE oxide on the recrystallization process and high-temperature properties of molybdenum plate were analyzed.The results show that the rolling process of La-Mo alloy plate should appropriately enhance blooming temperature,hot-rolling finishing temperature,warm rolling temperature and annealing temperature before cold rolling,compared with that of pure molybdenum plate.The recrystallization temperature of molybdenum plate was significantly enhanced because of the existence of La₂O₃,and would increase with increasing the content of La₂O₃.The recrystallization temperature of La-Mo alloy plate with the content of 0.54wt%increased about 600℃compared with than that of pure molybdenum plate.Tensile strength and elongation of the molybdenum plate were significantly enhanced by the existence of La₂O₃.