The invention belongs to the technical field of ultrahigh-temperature
ceramic materials, and discloses a high-purity
porous tantalum carbide ceramic and a preparation method and application thereof.The preparation method comprises the steps that a porous
graphite substrate is horizontally placed in a vertical vapor
deposition chamber, after the chamber is vacuumized,
argon is introduced, the reaction air pressure is increased to 10-100 mbar, and the
graphite substrate is heated to the
deposition temperature of the
tantalum element; inorganic
tantalum salt and
hydrogen are conveyed into the cavity, and
tantalum element deposition of the first area is achieved;
argon is introduced into the
reaction chamber, the reaction air pressure is pressurized, the carrier gas flow of the inorganic tantalum salt is increased, the
deposition temperature of the tantalum element is increased, tantalum element deposition of the second area is achieved, and the process is repeated to achieve
sequential deposition of the tantalum element on the porous
graphite substrate from inside to outside; after the tantalum element is completely deposited, the high-purity porous
graphite substrate is heated and reacts to obtain
tantalum carbide,
reaction conditions are adjusted, so that reaction
airflow gradually permeates at different depths of the porous material, and Ta is uniformly deposited at different positions.