Air-stable compact of cobalt-rare earth alloy particles and method

Claim 1

A AIR-STABLE POROUS MAGNETIC COMPACT COMPRISED OF COMPACTED COBALT-RARE EARTH ALLOY PARTICLES, THE EXPOSED SURFACES OF SAID COMPACTED ALLOY PARTICLES HAVING A CONTINOUS ADHERENT COATING OF METAL WHICH IS INTERCONNECTING AN WHICH PROVIDES SAID COMPACT WIH AN EFFECTIVE BARRIER TO THE ATMOSPHERE, SAID MAGNETIC COMPACT BEING PRODUCED BY A PROCESS FOR DEPOSITING A SUBSTANTIALLY INTERCONNECTING ADHERENT COATING OF A METAL HAVING A MELTING POINT ABOVE 500*C ON THE EXPOSED SURFACES OF PRESSED PARTICLES OF COBALT-RARE EARTH ALLOY WITHOUT SIGNIFICANTLY DETERIORATING THEIR PERMANENT MAGNET PROPERTIES PRODUCING A MAGNTICALLY AIR-STABLE COMPACT WHICH COMPRISES PROVIDING PARTICLES OF COBALT-RARE EARTH ALLOY HAVING AN AVERAGE SIZE UP TO ABOUT 10 MICRONS, PROVIDING AN ORGANOMETALLIC COMPOUND WHICH IS A SOLID OR LIQUID AT ROOM TEMPERATURE AND WHICH AT A TEMPERATURE BELOW 500*C DECOMPOSES AND YIELDS PRODUCTS OF DECOMPOSITION CONSISTING OF GASEOUS NONMETALLIC PRODUCT AND A METAL VAPOR, ADMIXING SAID ORGANOMETALLIC COMPOUND AND SAID PARTICLES OF ALLOY TO FORM A SUBSTANTIALLY INTIMATE MIXTURE, SAID ORGANOMETALLIC COMPOUND BEING USED IN AN AMOUNT WHICH ON DECOMPOSITION PRODUCES THE METAL IN AN AMOUNT RANGING FROM 1 TO 5% BY WEIGHT OF SAID COBALT-RARE EARTH ALLOY PARTICLES, PRESSING SAID MIXTURE TO FORM A GREEN BODY, HEATING SAID GREEN BODY IN A SUBSTANTIALLY INERT ATMOSPHERE WHICH IS A FLOWING ATMOSPHERE OR A SUBSTANTIAL VACUUM AT A TEMPERATURE BELOW 500*C AND SUBSTANTIALLY COMPLETELY DECOMPOSING SAID ORGANOMETALLIC COMPOUND AND PRODUCING SAID GASEOUS PRODUCT OF DECOMPOSITION AND METAL VAPOR, SAID METAL VAPOR DEPOSITING A SUBSTANTIALLY INTERCONNECTING CONTINOUS COATING OF METAL HAVING A MELTING POINT ABOVE 500*C ON THE EXPOSED SURFACES OF SAID PRESSED PARTICLES SUBSTANTIALLY UNIFORMLY THROUGHOUT SAID BODY AND HAVING NO SIGNIFICANT DETERIORATING EFFECT ON THE MAGNETIC PROPERTIES OF SAID ALLOY PARTICLES, SAID DEPOSITED METAL SUPPORTING SAID PARTICLES AND POVIDING THE RESULTING COMPACT WITH AN EFFECTIVE BARRIER TO THE ATMOSPHERE, SAID NON-METALLIC GASEOUS PRODUCT OF DECOMPOSITION DIFFUSING AWAY FROM SAID BODY LEAVING THE RESULTING COMPACT POROUS IN AN AMOUNT RANGING FROM ABOUT 5 TO 40 PERCENT BY VOLUME OF SAID COMPACT.