Refractory metal cpds - of grps four,five,six metals by direct synthesis from the elements

摘要

Refractory compounds of Groups IV, V, VI metals with N2, C, B, Si, O2, P, S, F2 and Cl2 are obtained from mixed finely divided (0.1 to 100 mu) powder of the elements which are compressed to 2-4 g/cm3 and ignited using pyropyrophoric mixtures of CaSi2, Fe2O3, Mg, Al2O3, SiO2 Ti and B. These mixtures are fired with a tungsten or nichrome spiral wire. Zirconium nitride is prepared without a pyrophoric igniter. Yields of nitrides, oxides, chlorides and fluorides are improved by using the gases at 0.5-1000 atm. Yields of carbides, borides, silicides, phosphides and sulphides are increased by metalloid/metal ratios of 0.5:1 to 1:2.