A kind of preparation method of molybdenum slab

Abstract

The invention provides a method for preparing a molybdenum slab, comprising the following steps: Step 1: Mix and dry molybdenum dioxide powder and lanthanum nitrate solution to obtain lanthanum-doped molybdenum dioxide powder. Wherein the lanthanum content in the lanthanum-doped molybdenum dioxide powder is (0.75~1.5)%; Step 2, carries out hydrogen reduction, sieves the lanthanum-doped molybdenum dioxide powder, obtains the lanthanum-doped molybdenum powder; Step 3, mixes the lanthanum-doped molybdenum powder and Appropriate amount of pure molybdenum powder is mixed, and the lanthanum content after mixing is (0.3-1.0)%, and then compacted and sintered to obtain a lanthanum-doped molybdenum slab. The lanthanum-molybdenum-doped slab prepared by the method has fine and uniform grains, no coarse-grain structure, and the surface is bright after being rolled into a molybdenum sheet, without defects such as trachoma, holes, and snowflake crystals, and the surface quality is good; by controlling the concentration of the lanthanum nitrate solution The lanthanum content of the lanthanum-doped molybdenum powder can be accurately controlled according to the dosage, so that the lanthanum content of the produced lanthanum-doped molybdenum slab can be accurately controlled, and the rolling processing performance is stable.

Description

technical field [0001] The invention belongs to the technical field of hard alloy preparation, and in particular relates to a method for preparing a lanthanum-molybdenum slab. Background technique [0002] Molybdenum plates (sheets) are widely used in the production of molybdenum boats, heat shields for high-temperature furnaces, structural parts and heating elements, electric light source parts and vacuum devices. Pure molybdenum slab has the disadvantages of low recrystallization temperature and poor comprehensive mechanical properties. The molybdenum plate (sheet) rolled by pure molybdenum slab has the phenomenon of recrystallization embrittlement, high room temperature brittleness, and high plastic brittle transition temperature, which greatly limit its application. [0003] In order to improve the performance of molybdenum plates (sheets), a certain amount of rare earth elements are usually added to molybdenum slabs, especially after adding rare earth lanthanum, it can...

AI Technical Summary

Problems solved by technology

The first method is that ammonium paramolybdate solution is formulated into ammonium paramolybdate solution, and then ammonium paramolybdate is obtained through evaporation and crystallization. During the evaporation and crystallization process, segregation is very easy to occur, which affects the uniformity of the components and even affects the quality of the product.

Its two, when adding the filtered lanthanum nitrate solution, and making doped ammonium paramolybdate through suction filtration and dehydration, part of the lanthanum nitrate solution will be lost together with the mother liquor during suction filtration, so that the mixed lanthanum The content is difficult to control accurately; in addition, the doped molybdenum powder obtained by using ammonium paramolybdate as the raw material has poor formability, and a molding agent needs to be added when pressing the blank

Therefore, the method has problems such as difficulty in accurately controlling the effective amount of rare earth lanthanum, large waste, poor uniformity of each component in the powder, and poor formability.

[0005] In summary, the method of doping the rare earth lanthanum element into molybdenum has a great influence on the quality of the obtained lanthanum-doped molybdenum slab. In the prior art, there are generally problems such as uneven doping of lanthanum element, uncontrollable doping amount, Unstable product performance and other issues

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