In the past, in the process of smelting or electrolysis, it usually uses the crucible that is welded by tungsten, molybdenum and tantalum plate. Because this kind of crucible has defects and shorter service life, especially for high temperature, high purity earth metals, tantalum material consumption is larger, production cost is higher. In view of this situation, the development of the whole tungsten crucible was carried out by Zhengzhou Sanhui Trading Co., Ltd. So far, the high quality tungsten crucible has been successfully produced, and the effect is satisfactory.
The production of powder metallurgy tungsten crucible, mechanical pressing and other methods can not meet the requirements, the reason is that the high diameter ratio is big, the suppression of the density is nonuniform, and the mold unloading is difficult. For this purpose, the design of the core module is selected. Whether the core design is reasonable is the key to the formation of tungsten crucible. If the core mold design is improper, it will appear the change of core mold and the cracking in the excessive part of the bottom of the tungsten crucible and the crucible wall. Therefore, when choose the core mold, the wall thickness shall have a certain strength. Since the tungsten crucible is a whole with the bottom side, there is a transitional zone between the bottom and the wall, so the circular arc must be used in this zone to prevent the concentration of the stress in this zone in the suppressing process of the tungsten crucible. If the arc transition is too small, there will be a small crack in the site after the formation of the tungsten crucible, so that the bottom and wall will be broken off. At the same time, in order to facilitate the mold unloading, it should be a certain angle along the bottom of the mold to the top.
The character of service of this tungsten crucible is good, it can be used to replace tantalum plate welding crucible, so that the cost can be greatly reduced.