Magnetic materials and permanent magnets

Claim 2

An anisotropic magnetic material having a mean crystal grain size of at least about 1 micron, an intrinsic coercivity of at least 1 kOe and having a maximum energy product of at least 10 MGOe upon sintering, said material consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe, in which at least 50 vol % of the entire material is occupied by a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure.

Claim 3

A sintered anisotropic permanent magnet having maximum energy product of at least 10 MGOe and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe.

Claim 4

A sintered anisotropic permanent magnet having maximum energy product of at least 10 MGOe and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe.

Claim 5

A sintered anisotropic permanent magnet having a mean crystal grain size of at least about 1 micron and consisting essentially of, by atomic percent 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe, in which at least 50 vol % of the entire magnet is occupied by a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure, said magnet having a maximum energy product of at least 10 MGOe.

Claim 6

A sintered anisotropic permanent magnet having a mean crystal grain size of at least about 1 micron and consisting essentially of, by atomic percent 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe, in which at least 50 vol % of the entire magnet is occupied by a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure, said magnet having a maximum energy product of at least 10 MGOe.

Claim 7

A permanent magnet as defined in claim 3, which contains no less than 1 vol % of nonmagnetic phases.

Claim 8

A permanent magnet as defined in claim 2 or 3, in which the mean crystal grain size is in the range of from 1 to 80 microns.

Claim 9

A permanent magnet as defined in claim 5, in which the mean crystal grain size is in the range of from 2 to 40 microns.

Claim 10

A permanent magnet as defined in claim 2 or 3 in which Sm is no more than 2 atomic percent in the entire magnet.

Claim 11

A permanent magnet as defined in claim 2 or 3, in which R is about 15 atomic percent, and B is about 8 atomic percent.

Claim 12

A permanent magnet as defined in claim 2 or 3, in which the maximum energy product is no less than 20 MGOe.

Claim 13

A permanent magnet as defined in claim 9, in which the maximum energy product is no less than 30 MGOe.

Claim 14

A permanent magnet as defined in claim 10, in which the maximum energy product is no less than 35 MGOe.

Claim 15

An anisotropic magnetic material having a mean crystal grain size of at least about 1 micron and an intrinsic coercivity of at least 1 kOe and having a maximum energy product of at least 10 MGOe upon sintering, said material consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B, at least one additional element M selected from the group given below in the amounts of no more than the atomic percentages specified below wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe, in which a crystal phase of a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure occupies at least 50 vol % of the entire material: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf. ______________________________________

Claim 16

An anisotropic magnetic material having a mean crystal grain size of at least about 1 micron and an intrinsic coercivity of at least 1 kOe and having a maximum energy product of at least 10 MGOe upon sintering, said material consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B, at least one additional element M selected from the group given below in the amounts of no more than the atomic percentages specified below wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe, in which a crystal phase of a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure occupies at least 50 vol % of the entire material: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf. ______________________________________

Claim 17

A sintered anisotropic permanent magnet having a maximum energy product of at least 10 MGOe and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at leat one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B, at least one additional element M selected from the group given below in the amounts of no more than the atomic percentages specified below, wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe,: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf. ______________________________________

Claim 18

A sintered anisotropic permanent magnet having a maximum energy product of at least 10 MGOe and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at leat one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B, at least one additional element M selected from the group given below in the amounts of no more than the atomic percentages specified below, wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe,: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf. ______________________________________

Claim 19

A sintered anisotropic permanent magnet having a mean crystal grain size of at least about 1 micron and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B, at least one additional element M selected from the group given below in the amounts no more than the atomic percentages specified below, wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf ______________________________________ in which a crystal phase of a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure occupies at least 50 vol % of the entire magnet, said permanent magnet having a maximum energy product of at least 10 MGOe.

Claim 20

A sintered anisotropic permanent magnet having a mean crystal grain size of at least about 1 micron and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B, at least one additional element M selected from the group given below in the amounts no more than the atomic percentages specified below, wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf ______________________________________ in which a crystal phase of a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure occupies at least 50 vol % of the entire magnet, said permanent magnet having a maximum energy product of at least 10 MGOe.

Claim 21

A permanent magnet as defined in claim 14, which contains no less than 1 vol % of nonmagnetic phases.

Claim 22

A permanent magnet as defined in claim 13 or 14, in which the mean crystal grain size is in the range of from 1 to 90 microns.

Claim 23

A permanent magnet as defined in claim 16, in which the mean crystal grain size is in the range of from 2 to 40 microns.

Claim 24

A permanent magnet as defined in claim 13 or 14, in which Sm is no more than 2 atomic percent in the entire magnet.

Claim 25

A permanent magnet as defined in claim 13 or 14, in which R is about 15 atomic percent, and B is about 8 atomic percent.

Claim 26

A permanent magnet as defined in claim 13 or 14, in which the maximum energy product is no less than 20 MGOe.

Claim 27

A permanent magnet as defined in claim 20, in which the maximum energy product is no less than 30 MGOe.

Claim 28

A permanent magnet as defined in claim 21, in which the maximum energy product is no less than 35 MGOe.

Claim 29

A magnetic material as defined in claim 1 or 12, wherein R is about 15 at % and B is about 8 at %.

Claim 30

A sintered anisotropic permanent magnet as defined in claim 3 or 14 wherein said Fe--B--R type tetragonal crystal structure has the lattice constants a o of about 8.8 angstroms and c o of about 12 angstroms.

Claim 31

A permanent magnet as defined in claim 13 or 14 wherein said additional elements M is at least one selected from the group consisting of V, Nb, Mo, W and Al.

Claim 32

A magnet as defined in claim 25, wherein said additional elements M is contained no more than the amount by atomic percent as specified below: ______________________________________ 3.7% V, 6.2% Nb, 4.0% Mo, 3.7% W, and 3.4% Al; ______________________________________ wherein the sum of M is no more than the maximum value of any one of the values specified above for M actually added.

Claim 33

A magnetic article in the form of powder compact or sintered mass of the magnetic material as defined in any of claims 1 and 12.

Claim 34

A sintered anisotropic permanent magnet as defined in claim 2, 3, 13 or 14, wherein Si is present in an amount of at most 5 at %.

Claim 35

A powdery magnetic material capable of uniaxial alignment upon orientation in a magnetic field to provide magnetic anisotropy, and having a maximum energy product of at least 10 MGOe and an intrinsic coercivity of at least 1 kOe upon sintering, said material having a mean crystal grain size of at least about 1 micron, and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe, in which at least 50 vol % of the entire material is occupied by a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure.

Claim 36

A powdery magnetic material capable of uniaxial alignment upon orientation in a magnetic field to provide magnetic anisotropy, and having a maximum energy product of at least 10 MGOe and an intrinsic coercivity of at least 1 kOe upon sintering, said material having a mean crystal grain size of at least about 1 micron, and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4-24 percent B and the balance being at least 56 percent Fe, in which at least 50 vol % of the entire material is occupied by a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure.

Claim 37

A powdery magnetic material capable of uniaxial alignment upon orientation in a magnetic field to provide magnetic anisotropy, and having a maximum energy product of at least 10 MGOe and an intrinsic coercivity of at least 1 kOe upon sintering, said material having a mean crystal grain size of at least about 1 micron, and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4--24 percent B, at least one additional element M selected from the group given below in the amounts of no more than the atomic percentages specified below wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe, in which crystal phase of a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure occupies at least 50 vol % of the entire material: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf. ______________________________________

Claim 38

A powdery magnetic material capable of uniaxial alignment upon orientation in a magnetic field to provide magnetic anisotropy, and having a maximum energy product of at least 10 MGOe and an intrinsic coercivity of at least 1 kOe upon sintering, said material having a mean crystal grain size of at least about 1 micron, and consisting essentially of, by atomic percent, 12-20 percent R wherein R is at least one element selected from the group consisting of Nd, Pr, La, Ce, Tb, Dy, Ho, Er, Eu, Sm, Gd, Pm, Tm, Yb, Lu and Y and wherein at least 50% of R consists of Nd and/or Pr, 4--24 percent B, at least one additional element M selected from the group given below in the amounts of no more than the atomic percentages specified below wherein the sum of M is no more than the maximum value of any one of the values specified below for M actually added and the balance being at least 56 percent Fe, in which crystal phase of a ferromagnetic compound having a Fe--B--R type tetragonal crystal structure occupies at least 50 vol % of the entire material: ______________________________________ 3.3% Ti, 4.5% Ni, 5.0% Bi, 6.6% V, 10.0% Nb, 8.4% Ta, 5.6% Cr, 6.2% Mo, 5.9% W, 3.5% Mn, 6.4% Al, 1.4% Sb, 4.5% Ge, 1.8% Sn, 3.7% Zr, and 3.7% Hf. ______________________________________

Claim 39

A sintered anisotropic permanent magnet as defined in claim 2, 3, 13 or 14, wherein R is Nd.

Claim 40

A magnetic material as defined in claim 1, 12, 24 or 30 wherein said Fe--B--R type tetragonal crystal structure has the lattice constants a o of about 8.8 angstroms and c o of about 12 angstroms.

Claim 41

A magnetic article in the form of powder compact or sintered mass of the magnetic material as defined in claim 32.

Claim 42

A magnet or material as defined in claim 1, 2, 3, 12, 13, 14, 29 or 30 which is substantially Co-free.

Claim 43

A magnet or material as defined in claim 1, 3, 12, 14, 29 or 30 wherein oxygen is present in an amount of not more than 1 at %.