In order to prepare niobium-tungsten alloy powder with uniform particle size distribution, low oxygen and nitrogen content and high powder sphericity, a new preparation method was proposed. This method can also make up for the shortcomings of traditional technology, such as complicated process, uncontrollable process parameters and easy introduction of impurity elements.
A new production process of niobium-tungsten alloy powder:
1) Preparation of pre-alloy bar: tungsten, niobium, molybdenum, zirconium and other metal materials are hot melted to form niobium-tungsten alloy liquid, and the niobium-tungsten alloy liquid is cast or forged to form niobium-tungsten alloy pre-alloy bar, and its coaxiality is less than 0.05mm;
2) The surface of niobium-tungsten alloy pre-alloy rod is treated to ensure no pollution on the surface;
3) Vacuumizing and replacing inert gas: vacuumizing the smelting chamber prepared by the niobium-tungsten alloy powder, the limit vacuum is 0.3 Pa ~ 0.5 Pa, and replacing the smelting chamber prepared by the alloy powder system with inert gas 2 ~ 3 times;
4) Smelting: Adopt the way of no crucible induction heating coil melted niobium tungsten alloy alloy bars, the parameters of the induction coil (from 1, 2, 3, phi n) for (50100,10,3), adjust the power, make the niobium tungsten alloy melt pre alloy bars and produces continuous metal droplet, among them, the phi 1 to the bottom of the induction coil circle diameter, phi 2 for induction coil top circle diameter, φ3 is the inner diameter of induction coil, n is the number of turns of induction coil;
5) atomization: an open atomizer is used to atomize the metal droplets to form niobium tungsten alloy powder;
6) Screening and classification: under inert gas protection, different mesh screens are used for screening and classification of niobium tungsten alloy powder.
Note: The chemical composition of the niobium-tungsten alloy in step (1) in percentage by weight is: The content of W is 4.5 ~ 5.5%, Mo is 1.7 ~ 2.3%, Zr is 0.7 ~ 2.2%, O is less than or equal to 0.01%, H is less than or equal to 0.0015%, other impurities are less than 0.15%, the allowance is Nb, and its chemical composition is uniform.
