Hochtemperatur-Werkstoff

摘要

A high temperature material has a carbide phase based on niobium and/or tantalum carbide and a metal phase based on tungsten and/or molybdenum. The atomic percentages of the constituents are such that (a) is between 0 and 1, (b) is between 0 and 1, (c) C is between 5 and 40 and Ta + Nb is between U and V where U = 5.4 - 4.4 a - 5.15b + 0.94c + 5.15ab - 0.04 ac + 0.21 bc - 0.11 abc V = 56 - 5a - 37b + 5ab + 0.15 ac + 0.9 bc - 0.3 abc. Up to 90 mol per cent of the niobium or tantalum may be replaced by hafnium, zirconium or titanium or mixtures thereof. The carbide phase may also include up to 40 mol per cent tungsten and/or molybdenum carbide and the metal phase may include up to 60 at. per cent niobium and/or up to 30 at. per cent tantalum. Up to 5% by weight or iron group metals may be included. The material may be produced by pressing a powder including an iron group metal and vacuum sintering the compact e.g. at 1530-1650 DEG C. Alternatively, the powder may be pressed without the iron group metal, vacuum sintered at 1500-2200 DEG C and impregnated with Ag and/or Cu. As a further alternative, the metal phase may be in the form of fibres or even wire nets or grids to which the carbide is attached by sintering.