PROCEDURE FOR PRODUCTION OF MONO-CRYSTAL OF TUNGSTEN - TANTALUM ALLOY Russian patent published in 2012 - IPC C22C27/04 C30B13/22 

FIELD: metallurgy.

SUBSTANCE: powders of tungsten and tantalum are mixed and rods are manufactured by hydrostatic extrusion of the mixture at a pressure of 140÷160 MPa for 3÷5 minutes. Then the rods are heat treated in vacuum with residual pressure of P≤8·10-3 Pa at a temperature of 800 °C. Then the rods are continued to be processed in a reducing atmosphere at a surplus pressure of at least 0.2 atm and a temperature of 800÷1000 °C for not less than two hours. Then the rods are heat treated in vacuum with residual pressure of P≤8·10-3 Pa at a temperature of T≥1500°C for not less than 2 hours followed by cooling. Heating and cooling under vacuum and the reducing atmosphere are carried out at a rate of 300÷400 °C/h. A mono-crystal bar is grown by crucibleless melting by means of cathode ray heating it is finished by even heat with seed melting to the end of the bar of odd heat.

EFFECT: production of mono-crystals of tungsten tantalum alloy with a high degree of uniformity of distribution of tantalum along the bar.

3 cl, 1 tbl