| 摘要 |
In a method of making articles which are permanently resistant to mechanical and chemical stresses at high temperatures by infiltrating a porous body of refractory metal carbide with a metallic material, the porous body or skeleton is produced from a mixture of free-carbon containing titanium carbide powder and chromium powder in which mixture the major portions of the chromium and carbon are present as a solid solution of chromium carbide and titanium carbide and before compacting and sintering to form the skeleton, the particles of the mixture are coated with a metallic binder comprising cobalt nickel, iron or their alloys. In one example a powder mixture comprising carbide powder comprising 75.96 per cent. titan-carbide powder comprising 75.96 per cent. titanium 18.0 per cent. combined carbon and 2.53 per cent. free carbon, all of 325 mesh was placed in a graphite crucible and heated in dry hydrogen for 30 minutes at 2300 DEG C. and the agglomerated mass thus formed was crushed to pass a 140 mesh screen Ten per cent. by weight of carbonyl nickel powder was added as a binder and the mixture treated in a ball mill for 24 hours. The mixture was then hot-pressed to the required shape at 1650 DEG C. and sintered for one hour at 1500 DEG C. in dry hydrogen and finally infiltrated at 1530 DEG C. with a nickel chromium-iron alloy known under the Registered Trade Mark "Nichrome." In another example, the binder was cobalt powder and the infiltrant was a cobalt-chromium-molybdenum alloy. The amount of chromium powder added to the original mixture may be increased to 15 per cent.
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