The manufacturing process of tantalum tube is as follows:

Breakdown

Tantalum cannot be processed in the same way as ordinary metals. Generally, the initial process is forging, processing and heat treatment.

The flat slab or round medium and small blank can be made by hammering and punching. Unlike ordinary metals, tantalum cannot be processed hot. The recrystallization temperature of tantalum exceeds 1000~C. If heated, excessive oxidation will occur even if the general protective coating is made. What is more serious is that if tantalum is exposed to such a high temperature, not only will the surface of tantalum undergo excessive oxidation, but also oxygen can invade the atoms inside the matrix and make tantalum brittle. Not only oxygen, but even nitrogen, carbon and hydrogen can make tantalum brittle. Due to the above reasons, tantalum is generally not hot processed. When necessary, a protective coating or an inert gas atmosphere shall be applied.

Heat treatment

Since tantalum reacts actively with oxygen, it must be avoided in an atmosphere where even a little air is present

Heat treatment. Therefore, almost all annealing is done in a high vacuum and the furnace must be highly airtight. Generally, the heat treatment temperature of tantalum is generally 950~1300℃, and tantalum and commonly used tantalum alloy do not undergo phase transformation within this temperature range. Heat treatment is only used for annealing, so neither heating temperature nor cooling speed is important. In order to produce complete recrystallization, the heat treatment time is slightly longer.

Commercially produced tantalum has a high purity. The grains become very large by annealing. The size of crystal particles is determined by cold working, purity, temperature and process steps. Therefore, temperature control and process control are important means to determine the size of crystallization.

Unlike many other metals, tantalum must be very clean before heat treatment. If not cleaned very clean, will occur by hydrogen, oxygen, nitrogen and carbon surface pollution, become embrittlement (hardening) tissue. Since hydrogen, oxygen, nitrogen and carbon are very active infiltrating elements within the annealed temperature range of tantalum, once contaminated by these elements, no other way can be removed except re-smelting.