Preparation Method of Tungsten Molybdenum Alloy Crucible

Rare earth metal is an important resource and strategic resource in China. It is widely used in various fields and has been known as "industrial monosodium glutamate". Rare earth elements are highly active metals, which are usually difficult to be extracted from their compounds in general conditions. The electrolytic extraction requires the crucible and tungsten electrode.

Traditional tungsten crucibles or molybdenum crucibles generally adopt the mechanical compaction and sintering of the powder alloy mixture after mixing, which is characterized by high speed and high productivity. Because of the high hardness and brittleness of the tungsten material itself, the general casting and forging process is difficult to process and shape. Molybdenum is easily made, but the disadvantage is that the melting point is low, so it is not suitable for the production of large crucible products. So some scholars put the tungsten and molybdenum synthesis, joint preparation of tungsten molybdenum alloy crucible, the program is as follows:

Step one, the tungsten powder and molybdenum powder are pre treated and screened respectively. The size of tungsten powder is 0.6~20 microns after screening, and the size of molybdenum powder is 0.05~10 micron. The particle size of the molybdenum powder is 0.05~10 micron, and the tungsten powder and molybdenum powder after the sieve are mixed in accordance with the mass ratio of 1~9:1~9 to ball milling 1~5h, and then mixed at room temperature for 20h, obtained mixed tungsten and molybdenum powder, spare;

Step two, according to the needs of the crucible target size, weigh the quality or volume form a mixed powder of tungsten and molybdenum crucible required, and molding cavity and tungsten and molybdenum powder mixture volume of cold isostatic pressing mould, by feeding the molybdenum powder mixture forming cavity free fall into the cold isostatic pressing die out in the cold isostatic pressing process conditions: pressure 5~10min in 150~200MPa; after processing the powder are rough, spare;

Step three, demoulding, remove the powder blank, the car size machine processing, spare;

Step four, put the powder blank into the furnace body and heat up to 2150~2200 ℃ at the heating rate of 30~40 /min, and then heat the 8~9h at this temperature. Then the body is taken out after the natural cooling of the furnace to room temperature.

Step five, the blank after surface treatment by hot isostatic pressing treatment by tungsten molybdenum alloy crucible; the hot isostatic pressing process was as follows: preburning at 800 ~ 1000 ℃ for 30min, and then heating up to 1450 ~ 1500 ℃, 180 ~ 200MPa, holding pressure 1 ~ 3h.

The crucible is produced by mixing molybdenum keeps the high-temperature properties of tungsten, molybdenum and inherits the advantages of easy making, high dislocation density tungsten internal dislocation, intercrossed into cut order, to improve the strength of the product service life, is one of the solutions of the manufacturing tungsten molybdenum crucible.

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