Application of Pure Molybdenum Foil Strip
Pure molybdenum foil strip has high temperature strength, good thermal conductivity, low expansion coefficient and good machinability. Therefore, many special light bulbs and electric light source devices, such as automobile halogen tungsten lamp, high-pressure sodium lamp, lighting halogen tungsten lamp, etc., need to use pure molybdenum materials widely. Molybdenum Foil is an important material used to make the parts, such as hooks, core wires, lead wires, and plastic supports.
For example, molybdenum rod is the component of the special light bulb and electric light source.
Plus, the quartz glasses need a kind of gaseous sealing material in between. This gas seal material can bear sealing temperature up to 1700~ 1800 C. The pure molybdenum foil strip with a thickness between 0.02mm and 0.06mm is the ideal material to make this tungsten rod and sealing material.
However, the recrystallization temperature of pure molybdenum is 1000-1200 ℃. Therefore, brittleness and fracture often occur. Also, pure molybdenum has other defects, such as low strength at high temperature and deformation.
Those defects are because of the recrystallization grain of pure molybdenum that grows in the high temperature environment. The high temperature leads to the complex process and the phenomenon of crack edge and delamination. Thus, pure molybdenum foil strip has a low yield and a high price.
Cold Rolled Molybdenum Lanthanum Foil Strip
Lanthanum Molybdenum foil strip is a suitable alternate material for molybdenum foil strip. Lanthanum Molybdenum foil strip provides the advantages of excellent mechanical performance, high temperature strength, bending and brittle resistance and a high yield.
First, molybdenum and lanthanum materials are made into wire by traditional powder metallurgy or plastic processing. The weight ratio of lanthanum to molybdenum should be 0.2 % to 0.6 %.
Second, the electrolysis or chemical cleaning remove the graphite emulsion or scale on the surface of Mo-La wire. Then, a hydrogen-filled furnace anneals the molybdenum lanthanum wire under a temperature of 1300-1400 ℃.
Third, Mo-La wire is cold rolled at room temperature. The first deformation is 20-30%.
Fourth, the rolling is interrupted at the point when the deformation of rolling reaches 60-65%. Intermediate annealing of molybdenum lanthanum wire between 900~ 1100 ℃.
Fifth, the intermediate annealed Mo-La strip has finished the rolling at room temperature.