Method for preparing square tungsten-yttrium blank

Abstract

The invention discloses a method for preparing tungsten-yttrium square billets, which comprises the following steps: a. dispersing yttrium nitrate aqueous solution in a spraying mode evenly and coating the yttrium nitrate aqueous solution on the surface of ammonium paratungstate, and performing mixing agitation, heating, and drying at the same time to obtain tungsten-yttrium coating powder after drying; and b. performing primary and secondary reductions, compaction, presintering and incipient fusion sintering on the tungsten-yttrium coating powder to be prepared into the uniform tungsten-yttrium square billets with metallicity, wherein the incipient fusion sintering process comprises that the temperature is increased for 10 to 30 minutes and the temperature is kept for 20 to 50 minutes, and the electric current in the process of keeping the temperature is between 2,500 and 4,000 amperes. The method has a simple process and prepares the tungsten-yttrium coating powder by adopting the spraying mode, thus the even distribution degree of elements added to square billet raw materials is ensured, and the tungsten-yttrium coating powder with comparatively even dispersion; besides, the process of the subsequent incipient fusion sintering is controlled to raise the temperature for 10 to 30 minutes, keep the temperature for 20 to 50 minutes, and keep the electric current in the process of keeping the temperature between 2,500 and 4,000 amperes, thus each point of the prepared tungsten-yttrium square billets is volatilized evenly; and under the cooperation of the method and the incipient fusion sintering, the prepared tungsten-yttrium square billets have good evenness.

Description

technical field [0001] The invention relates to the preparation technology of tungsten yttrium billets, in particular to a method for preparing uniform tungsten yttrium billets. Background technique [0002] Tungsten electrode material is one of the key materials used in TIG and PLSMA technology. There are many types of tungsten electrodes currently used in industry. For example: cerium tungsten electrode, lanthanum tungsten electrode, thoriated tungsten electrode, etc. Among the widely used tungsten electrodes, thoriated tungsten electrodes show better performance. However, since thorium is a radioactive substance, it will cause cumulative radioactive hazards to the human body and radioactive pollution to the environment. Therefore, the currently developed tungsten-yttrium electrode can replace the radioactive thoriated tungsten electrode in the technical field of TIG and PLSMA. [0003] The research and development of new electrode materials and the actual application r...

AI Technical Summary

Problems solved by technology

The preparation of tungsten yttrium electrode is realized by preparing tungsten yttrium billet. In the past, tungsten yttrium billet was directly added to metal tungsten powder for batch mixing to obtain tungsten yttrium coated powder, and then pressed to obtain tungsten yttrium billet. In practice, evaporation pots and ovens are often used to prepare tungsten-yttrium-coated powders, but because this process cannot prepare uniform tungsten-yttrium-coated powders, resulting in the use of tungsten-yttrium-coated powders. billet is not uniform

Moreover, due to equipment and process reasons, the volatilization point of vertical melting sintering for preparing tungsten-yttrium billet is not strictly controlled, resulting in uneven volatilization of each point of tungsten-yttrium billet, and it is impossible to obtain tungsten-yttrium billet with good uniformity, which in turn leads to The performance of the tungsten yttrium electrode made of this tungsten yttrium billet (such as: performance in medium and high current penetration, etc.) cannot meet the corresponding requirements

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