PROCESS FOR PREPARING HAFNIUM Russian patent published in 1997 - IPC

FIELD: metallurgy of rare metals. SUBSTANCE: process is carried out by calcium thermal reduction with hafnium tetrafluoride in inert medium at 20-450 C in the presence of metal that forms binar alloy with hafnium, and the whole is then removed by heating in vacuum. Prior to reduction operation, the blank is vacuum treated at 20-350 C, and reduction is carried out in the presence of metal that reduces temperature of binar alloy to 1125-1900 C and this metal is removed by electron beam melting and the melt is heated to temperature by 200-900 C higher. Calcium is used in 5-20% excess of stoichiometric amount. The metal being added is beryllium in amount of 1.2-4.0%, 1.7-5.0 cobalt; 3.1-1.0 iron; 3.5-10.0 aluminium; 4.5-19.0% copper; 7.8-17.0%; 6-18% manganese; 7.7-20.0% vanadium 7.7-20.0. EFFECT: more efficient preparation process. 1 tbl