Iron-rare earth-boron permanent magnets by hot working

Claim 3

A method of making a permanent magnet according to claim 1, in which the hot working is carried out at an elevated temperature and pressure and for a time sufficient to consolidate the material into a fully densified body, so as to cause plastic flow of at least a portion of the body and to form a fine grained, crystalline microstructure, so that said resultant body upon cooling is magnetically anisotropic and exhibits said permanent magnet characteristics.

Claim 4

A method of making a permanent magnet according to claim 1, in which an overquenched solid material comprising iron, neodymium and/or praseodymium, and boron is heated above 700°C, and is subjected to sufficient pressure to hot work it into a nonporous body, if necessary, and to cause plastic flow of the body; and the body is then immediately cooled, the duration and degree of hot working and rate of cooling being such that said resultant body has a fine grain microstructure, is magnetically anisotropic and exhibits magnetic coercivity.

Claim 5

A method of making a permanent magnet according to claim 1, in which an amorphous to finely crystalline material comprising iron, neodymium and/or praseodydium and boron is subjected to a hot die upsetting process at an elevated temperature and pressure to cause plastic flow in the body and to yield a fine grained, crystalline microstructure, whereby said resultant body upon cooling is magnetically anisotropic and exhibits said permanent magnet characteristics,preferred magnetic directions in the resultant body being parallel to the die upset press direction.

Claim 6

A method of making a permanent magnet according to claim 1, in which a melt-spun molten mixture consisting essentially of iron, neodymium and boron is quenched at such a rate as to form an overquenched, thin, solid ribbon material, pieces of the ribbon material are hot worked at an elevated temperature and pressure and for a time sufficient to consolidate the pieces into a fully densified body, to cause plastic flow of at least a portion of the body and to form a fine grained, crystalline microstructure, so that said resultant body upon cooling is magnetically anisotropic and exhibits said permanent magnet characteristics.

Claim 7

A fully densified, fine grain, anisotropic, permanent magnet, characterised in that the magnet is formed by hot consolidation and hot working of amorphous or fine grained material comprising iron, neodymium and/or praseodymium and boron.

Claim 8

A fully densified, fine grain, anisotropic, permanent magnet, characterised in that the magnet is formed by hot consolidation and hot working of amorphous or fine grained material comprising iron, neodymium and/or praseodymium and boron.

Claim 9

A fine grain anisotropic permanent magnet,characterised in that the magnet is formed by hot die upsetting a material comprising iron, neodymium and/or praseodymium and boron, the preferred magnetization direction of the resultant magnet being parallel to the die upset press direction.

Claim 10

A fine grain anisotropic permanent magnet,characterised in that the magnet is formed by hot die upsetting a material comprising iron, neodymium and/or praseodymium and boron, the preferred magnetization direction of the resultant magnet being parallel to the die upset press direction.

Claim 11

An anisotropic permanent magnet, characterised in that the magnet is formed by hot plastic deformation of an amorphous or fine grained alloy consisting essentially of, on an atomic percent basis, 50 to 90% iron, 10 to 50% neodymium and/or praseodymium, and 1 to 10% boron, the preferred magetization direction being substantially transverse to the directions of material flow during said deformation.

Claim 12

An anisotropic permanent magnet, characterised in that the magnet is formed by hot plastic deformation of an amorphous or fine grained alloy consisting essentially of, on an atomic percent basis, 50 to 90% iron, 10 to 50% neodymium and/or praseodymium, and 1 to 10% boron, the preferred magetization direction being substantially transverse to the directions of material flow during said deformation.