METHOD FOR MANUFACTURE OF TANTALUM TAPE Russian patent published in 2003 - IPC

FIELD: plastic working of metals. SUBSTANCE: method involves jacketing tantalum ingot; heating to temperature of 920-960 C; providing extrusion through flat slit- type die or extrusion through slit-type die and rolling to produce blank with total deformation of at least 60%; performing recrystallization annealing at temperature of 1,150-1,550 C for at least 2 hours and rolling blank or settling with total deformation of at least 60%; providing intermediate recrystallization annealing at temperature of 900-1,200 C for at least 2 hours and rolling or settling deformation and final recrystallization annealing at temperature of 850- 1,150 C for 0.1-30 min at maximal heating rate and pressure in vacuum furnace not in the excess of 2×10^-4 mm of mercury column; cooling to temperature of 780-800 C for time interval, which does not exceed 20% of final recrystallization annealing time. Except for final annealing, each subsequent annealing process is conducted at temperature not in the excess of previous temperature. Cooling after final annealing process is conducted in furnace or by directing inert gas through annealing furnace or by performing final recrystallization annealing process in continuous furnace. In order to reduce anisotropy of tantalum mechanical properties, cross rolling is provided after at least one recrystallization annealing process. Method allows tantalum tape to be produced with thickness of 0.25 mm, with uniform non-textured recrystallized grain of 7-9 number and elasticity IE=3.7-4.3 mm. Method is used for manufacture of articles from high-melting point metals, for example, in electronic industry for manufacture of electrolytic condenser parts. EFFECT: improved quality of tantalum tape and increased metal utilization coefficient. 6 cl