The invention relates to a heat treatment method for tantalum crucible, which can reduce and eliminate the phenomenon of the brittle crack of tantalum crucible and prolong the service life of tantalum crucible. In order to achieve the above purpose, the invention adopts the following technical scheme: a tantalum crucible heat treatment method. The tantalum crucible is placed in an atmosphere with alkali earth metal and alkali metal for high temperature heat treatment. Further, the heat treatment is performed at a temperature of 700°C and 1050°C. Further, the high temperature heat treatment is maintained for at least 5 hours. Further, the high temperature heat treatment is maintained for at least 5 20 hours. Further, the high temperature heat treatment is carried out in an atmosphere of argon gas. Further, at least 50 grams of the alkali metal is added and at least 100 grams of the alkaline earth metal is added. The beneficial effect of the invention is that the service life of the tantalum crucible after heat treatment according to the method of the invention is prolonged. Heat treatment method of tantalum crucible.
The commonly used production method of tantalum powder is to reduce potassium fluoride tantalate with sodium to get the raw powder. The raw powder obtained by reduction is generally subjected to vacuum heat treatment at the high temperature of 800°C and 1500°C to purify the raw powder and improve its physical properties. In order to ensure that tantalum powder is not contaminated, the heat treatment of tantalum powder is usually carried out by using tantalum crucible (tantalum crucible) to contain tantalum powder. In the process of heat treatment, the tantalum crucible is repeatedly subjected to the cyclic thermal impact of vacuum heating and atmospheric contact cooling. After repeated thermal cycles and adsorption of oxygen, nitrogen, carbon monoxide and carbon dioxide, the grains of tantalum crucible are coarser and the intercalation elements are enriched to grain boundaries, resulting in brittle crack of tantalum crucible. Thus, the service life of tantalum crucible is short, resulting in high production cost of tantalum powder.
In order to solve the above problems, the invention provides a heat treatment method of tantalum crucible, which can reduce and eliminate such brittle crack phenomenon of tantalum crucible and extend the service life of tantalum crucible. In order to achieve the above purpose, the invention adopts the following technical scheme: a tantalum crucible heat treatment method. The tantalum crucible is placed in an atmosphere with alkali earth metal and alkali metal for high temperature heat treatment. Further, the heat treatment is performed at a temperature of 700°C and 1050°C. Further, the high temperature heat treatment is maintained for at least 5 hours. Further, the high temperature heat treatment is maintained for at least 5 20 hours. Further, the high temperature heat treatment is carried out in an atmosphere of argon gas. Further, at least 50 grams of the alkali metal is added and at least 100 grams of the alkaline earth metal is added. The beneficial effect of the invention is that the service life of the tantalum crucible after heat treatment according to the method of the invention is prolonged.
