Process of making fluid-permeable article

Claim 1

A PROCESS OF MAKING A LIQUID PERMEABLE POWDERED METAL ARTICLE OF MANUFACTURE COMPRISING MIXING PARTICLE OF A METAL WHICH IS INFILTRATABLE INTO THE METAL OF WHICH THE POWDERED METAL ARTICLE IS TO BE MADE, IN APPROXIMATELY EQUAL PROPORTIONS WITH PARTICLES OF A METAL WHICH IS NONINFILTRATABLE INTO THE METAL OF WHICH THE POWDERED METAL ARTICLES IS TO BE MADE TO FORM A COMPOSITE POWDERED METAL MIXTURE, MOLDING SAID COMPOSITE POWDERED METAL MIXTURE INTO A CORE WITH A NON-INFILTRATABLE METAL PARTICLES DISPOSED IN CLOSE PROXIMITY TO ONE ANOTHER, EMBEDDING SAID CORE IN A MASS OS FINER-GRAINED POWDERED METAL THAN THE POWDERED METAL MIXTURE OF SAID CORE, COMPRESSING SAID MASS TO FORM A SEMI-FINISHED BODY AND CORE ASSEMBLY, AND SINTERING SAID ASSEMBLY TO INFILTRATE THE INFILTRATABLE CORE METAL INTO SAID BODY AND TO CAUSE THE NON-INFILTRABLE METAL PARTICLES OF THE CORE TO ENGAGE AND ADHERE TO ONE ANOTHER WHEREBY TO PROVIDE A CHAMBER IN SAID BODY HAVING A PERMEABLE CELLULAR STRUCTURE OF NON-INFILTRATABLE METAL THEREIN HAVING A SPONGE-LIKE APPEARANCE.