Method of making a porous sealing device

Claim 1

THE METHOD OF FORMING A COMPRESSIBLE POROUS MATRIX WHICH COMPRISES THE STEPS OF BLENDING A METALLIC POWDER AND A VOLATILE POWDER FORMING A SUBSTANTIALLY UNIFORM POWDER MASS CONTAINING FROM ABOUT 40% TO ABOUT 75% BY VOLUME OF SAID VOLATILE POWDER, SAID METALLIC POWDER HAVING A SIZE RANGING FROM ABOUT 20 MICRONS TO ABOUT 177 MICRONS, SAID VOLATILE POWDER HAVING A SIZE RANGING FROM 105 MICRONS AT ABOUT 420 MICRONS, HEATING SAID POWDER MASS TO AN ELEVATED TEMPERATURE FOR A PERIOD OF TIME SUFFICIENT TO SINTER AND TENACIOUSLY BOND THE PARTICLES OF SAID METALLIC POWDER INTO A POROUS NETWORK AND TO VOLATILIZE SAID VOLATILE POWDER FORMING A POROUS MATRIX HAVING A PLURALITY OF PORES THEREIN CORRESPONDING SUBSTANTIALLY TO THE SPACES FORMERLY OCCUPIED BY THE PARTICLES OF SAID VOLATILE POWDER, AND THEREAFTER IMPREGNATING SAID MATRIX WITH A SOLID LUBRICANT FORMING A THIN LAYER THEREOF ON THE SURFACES OF SAID MATALLIC POWDER COMPRISING SAID NETWORK.