Thermally resistant articles and method for their fabrication

Claim 1

THE METHOD FOR COATING THE SURFACES OF ARTICLES COMPRISED OF CARBON WITH A TIGHTLY ADHERENT, CONTINUOUS, BIDE, WHICH CONSISTS IN APPLYING TO THE SURFACE TO BE COATED A CONTINUOUS FILM OF A PLASTIC MASS CONSISTING ESSENTIALLY OF A SUBSTANTIALLY HOMOGENEOUS MIXTURE OF ABOUT 100 PARTS BY WEIGHT OF FINELY DIVIDED CARBON NOT MORE THAN ABOUT 50 MICRONS IN DIAMETER, ABOUT 100 TO 500 PARTS BY WEIGHT OF FINELY DIVIDED SILICON CARBIDE NOT MORE THAN ABOUT 50 MICRONS IN DIAMETER AND ABOUT 5 TO 50 PARTS BY WEIGHT OF A FILM-FORMING POLYMER; STABILIZING THE FILM ON THE SAID SURFACE; AND SUBJECTING THE STABILIZED FILM TO A TEMPERATURE IN THE RANGE OF ABOUT 3000 TO 4000*F. IN THE PRESENCE OF AN AMOUNT OF MOLTEN SILICON AT LEAST SUFFICIENT TO REACT WITH ALL OF THE CARBON WHICH IS PRESENT IN THE FILM TO FORM SILICON CARBIDE THEREFROM, TO WET EACH PARTICLE OF SILICON CARBIDE WHICH IS PRESENT WITH SILICON, AND TO FILL ALL VOIDS IN THE SILICON CARBIDE STRUCTURE; AND CONTINUING THE SAID HEATING FOR A PERIOD OF TIME SUFFICIENT TO ELIMINATE THE SAID POLYMER AND CONVERT THE STABILIZED FILM TO SILICONIZED SILICON CARBIDE. IMPERMEABLE EXTERNAL COATING OF SILICONIZED SILICON CA