Method of producing high performance permanent magnets

Claim 1

A method of producing high performance permanent magnets characterized by an absence of cobalt, said method comprising the steps of (a) admixing particles of a master alloy consisting of Fe 2 B with Fe powder and particles of a rare earth capable of combining with Fe and B to form a tetraganol compound of Fe 14 R 2 B, (b) compacting the admixture into a predetermined size and shape, and (c) forming a magnetic material of the Fe 2 B, Fe powder and rare earth which includes a major phase of at least one intermetallic compound consisting of Fe-R-B and having a tetragoval crystal structure while controlling the particle size of the crystal structure and imparting magnetic characteristics thereto by sintering the compacted admixture at a temperature within the range of about 700° C. to about 1000° C. for a time period within the range of about a fraction of 1 hour to 36 hours to produce a permanent magnet with high coercivity.

Claim 2

A method of producing high performance permanent magnets characterized by an absence of cobalt, said method comprising the steps of (a) admixing particles of a master alloy consisting of Fe 2 B with Fe powder and particles of a rare earth capable of combining with Fe and B to form a tetraganol compound of Fe 14 R 2 B, (b) compacting the admixture into a predetermined size and shape, and (c) forming a magnetic material of the Fe 2 B, Fe powder and rare earth which includes a major phase of at least one intermetallic compound consisting of Fe-R-B and having a tetragoval crystal structure while controlling the particle size of the crystal structure and imparting magnetic characteristics thereto by sintering the compacted admixture at a temperature within the range of about 700° C. to about 1000° C. for a time period within the range of about a fraction of 1 hour to 36 hours to produce a permanent magnet with high coercivity.

Claim 6

A method of producing high performance permanent magnets characterized by an absence of cobalt, said method comprising the steps of (a) forming milled particles of a master alloy consisting of Fe 2 B by melting and casting the master alloy and crushing and milling the cast master alloy to a particle size no larger than about 50 microns, (b) admixing the master alloy particles with Fe powder and particles of a rare earth capable of combining with the Fe and B to form a tetragonal compound of Fe 14 R 2 B, (c) compacting the admixture into a predetermined size and shape, (d) forming a magnetic material of the Fe 2 B, Fe powder and rare earth which includes a major phase of at least one intermetallic compound consisting of Fe-R-B and having a tetrogonal crystal structure while controlling the particle size of the crystal structure and imparting magnetic characteristics thereto by sintering the compacted admixture at a temperature within the range of about 700° C. to about 1000° C. for a time period within the range of about a fraction of 1 hour to 36 hours to produce a permanent magnet with high coercivity, and (e) heat treating the magnetic material at a temperature of about 550° to 650° C. for about a fraction of an hour to two hours to enhance the magnetic characteristics thereof.

Claim 7

A method of producing high performance permanent magnets characterized by an absence of cobalt, said method comprising the steps of (a) forming milled particles of a master alloy consisting of Fe 2 B by melting and casting the master alloy and crushing and milling the cast master alloy to a particle size no larger than about 50 microns, (b) admixing the master alloy particles with Fe powder and particles of a rare earth capable of combining with the Fe and B to form a tetragonal compound of Fe 14 R 2 B, (c) compacting the admixture into a predetermined size and shape, (d) forming a magnetic material of the Fe 2 B, Fe powder and rare earth which includes a major phase of at least one intermetallic compound consisting of Fe-R-B and having a tetrogonal crystal structure while controlling the particle size of the crystal structure and imparting magnetic characteristics thereto by sintering the compacted admixture at a temperature within the range of about 700° C. to about 1000° C. for a time period within the range of about a fraction of 1 hour to 36 hours to produce a permanent magnet with high coercivity, and (e) heat treating the magnetic material at a temperature of about 550° to 650° C. for about a fraction of an hour to two hours to enhance the magnetic characteristics thereof.