Tantalum tungsten alloy is a kind of alloy with tantalum as the matrix and some tungsten elements added. Although both tantalum and tungsten can infinite solid solution, but when the tungsten content in more than 12-14 at % at % alloy plastic will be significantly reduced, when tungsten content is low, tantalum tungsten alloy as the pure tantalum low-temperature plastic, and has high strength, resistance to oxidation and corrosion resistant ability, so the lower content of tungsten tantalum tungsten alloy is widely used in aviation, aerospace, chemical industry, nuclear industry and other fields. For example, Ta-2.5W alloy can be used to manufacture heaters, cooling coils, heat exchangers and reactors, etc. Ta-7.5w alloy can be used to manufacture corrosion resistant elements; Ta-10W can be used as high temperature components such as thrust combustor of rocket engine and heating element of high temperature vacuum furnace.
At present, the preparation of tantalum-tungsten alloy blank usually requires several processes, such as mixing, pressing, sintering and melting.
The invention relates to a preparation method of tantalum tungsten alloy blank, which is characterized by the following steps:
The tantalum powder with an average particle size of 3 m ~ 5 m and tungsten powder with an average particle size of 3 m were used as raw materials, weighed and mixed according to the required proportion, and then the mixed powder was evenly mixed in a ball milling tank of a high-energy ball mill to obtain the mixed powder;
(2) Pressing the blank, pressing the mixed powder on the forming press with a pressure of 300MPa ~ 400MPa to get the blank block;
When the billet is crushed, put the billet into the ball grinding tank of the high-energy ball mill for crushing, and then the billet particles are obtained. The size of the billet particles is 0.1mm ~ 0.3mm;
In arc melting, put the billet particles into the crucible of arc melting furnace to close the furnace door, vacuum until the pressure in the furnace is lower than 0.003Pa, then stop vacuum pumping, fill high purity argon to 0.05mpa and vacuum pumping, repeat the above vacuum pumping steps for three times and then melt to get tantalum-tungsten alloy blank.
As an optimization, the ball grinding conditions described in step are as follows: the ball grinding medium is self-made 6mm tantalum ball with a diameter of 1:3 ~ 1:4, the mass ratio of tantalum ball into the powder is 1:3 ~ 1:4, the rotating speed of the high-energy ball mill is 400r/min ~ 600r/min, the steering adjustment time is 5min ~ 10min, and the ball grinding time is 60min ~ 120min.
