Abstract: Disclosed herein is a cooling roll which can provide bonded a magnet having excellent magnetic properties and having excellent reliability. A melt spinning apparatus is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and cooling roll 5 having a circumferential surface 53 in which dimple correcting means is provided. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5 in an inert gas atmosphere (ambient gas) such as helium gas, so that the molten alloy 6 is cooled and then solidified. In this process, dimples to be produced on a roll contact surface of the melt spun ribbon are divided by the dimple correcting means, thereby preventing formation of huge dimples.

Abstract: A magnetic material manufacturing method, a ribbon-shaped magnetic material manufactured by the method, a powdered magnetic material formed from the ribbon-shaped magnetic material and a bonded magnet manufactured using the powdered magnet material are disclosed. The method and the magnetic materials can provide magnets having excellent magnetic properties and reliability. A melt spinning apparatus 1 is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and a cooling roll 5 having a circumferential surface 53 on which dimple correcting means is provided. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5 in an inert gas atmosphere (ambient gas) such as helium gas, so that the molten alloy 6 is cooled and then solidified.

Abstract: Disclosed herein is a cooling roll which can provide bonded a magnet having excellent magnetic properties and having excellent reliability. A melt spinning apparatus is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and cooling roll 5 having a circumferential surface 53 in which dimple correcting means is provided. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5 in an inert gas atmosphere (ambient gas) such as helium gas, so that the molten alloy 6 is cooled and then solidified. In this process, dimples to be produced on a roll contact surface of the melt spun ribbon are divided by the dimple correcting means, thereby preventing formation of huge dimples.

Abstract: Disclosed herein is a cooling roll which can provide bonded a magnet having excellent magnetic properties and having excellent reliability. A melt spinning apparatus is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and cooling roll 5 having a circumferential surface 53 in which dimple correcting means is provided. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5 in an inert gas atmosphere (ambient gas) such as helium gas, so that the molten alloy 6 is cooled and then solidified. In this process, dimples to be produced on a roll contact surface of the melt spun ribbon are divided by the dimple correcting means, thereby preventing formation of huge dimples.

Abstract: A magnetic material manufacturing method, a ribbon-shaped magnetic material manufactured by the method, a powdered magnetic material formed from the ribbon-shaped magnetic material and a bonded magnet manufactured using the powdered magnet material are disclosed. The method and the magnetic materials can provide magnets having excellent magnetic properties and reliability. A melt spinning apparatus 1 is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and a cooling roll 5 having a circumferential surface 53 on which dimple correcting means is provided. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5 in an inert gas atmosphere (ambient gas) such as helium gas, so that the molten alloy 6 is cooled and then solidified.

Abstract: Disclosed herein is a magnetic powder which can provide magnets having excellent magnetic properties and having excellent reliability especially excellent heat stability. The magnetic powder is composed of an alloy composition represented by Rx(Fe1-aCOa)100-x-y-zByMz(where R is at least one kind of rare-earth element excepting Dy, M is at least one kind of element selected from Ti, Cr, Nb, V, Mo, Hf, W, Mn, Zr and Dy, x is 7.1-9.9 at %, y is 4.6-8.0 at %, z is 0.1-3.0 at %, and a is 0-0.

Abstract: Disclosed herein is a magnetic powder which can provide magnets having excellent magnetic properties and having excellent reliability especially excellent heat stability. The magnetic powder is composed of an alloy composition represented by Rx(Fe1-aCoa)100-x-y-zByMz (where R is at least one kind of rare-earth element excepting Dy, M is at least one kind of element selected from Ti, Cr, Nb, Mo, Hf, W, Mn, Zr and Dy, x is 7.1-9.9 at %, y is 4.6-8.0 at %, z is 0.1-3.0 at %, and a is 0-0.30, and the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, wherein when the magnetic powder is mixed with a binding resin and then the mixture is subjected to compaction molding to form a bonded magnet having a density &rgr;[Mg/m3], the maximum magnetic energy product (BH)max[kJ/m3] of the bonded magnet at a room temperature satisfies the relationship represented by the formula (BH)max/&rgr;2[×10−9 Jm3/g2]2.

Abstract: Disclosed herein is a magnetic powder which can provide a bonded magnet having high mechanical strength and excellent magnetic properties. The magnetic powder has an alloy composition containing a rare-earth element and a transition metal, wherein the magnetic powder includes particles each of which is formed with a number of ridges or recesses on at least a part of a surface thereof. In this magnetic powder, it is preferable that when the mean particle size of the magnetic powder is defined by a&mgr;m, the average length of the ridges or recesses is equal to or greater than a/40 &mgr;m. Further, preferably, the ridges or recesses are arranged in roughly parallel with each other so as to have an average pitch of 0.5-100 &mgr;m.

Abstract: Disclosed herein is a cooling roll which can provide bonded a magnet having excellent magnetic properties and having excellent reliability. A melt spinning apparatus 1 is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and a cooling roll 5 having a circumferential surface 53 in which gas expelling grooves 54 are formed. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 6 so as to be collided with the circumferential surface 53 of the cooling roll 5, so that the molten alloy 6 is cooled and then solidified. In this process, gas is likely to enter between a puddle 7 of the molten alloy 6 and the circumferential surface 53, but such gas is expelled by means of the gas expelling grooves 54.

Abstract: A method of manufacturing magnetic powder is disclosed. This method can provide magnetic powder from which a bonded magnet having excellent magnetic properties and reliability can be manufactured. A melt spinning apparatus 1 is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and a cooling roll 5. The cooling roll 5 is constructed from a roll base 51 and a circumferential surface 53 in which gas flow passages 54 for expelling gas are formed. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5, so that the molten alloy 6 is cooled and then solidified. In this process, gas is likely to enter between a puddle 7 of the molten alloy 6 and the circumferential surface 53, but such gas is expelled by means of the gas flow passages 54. The magnetic powder is obtained by milling thus formed melt spun ribbon 8.

Abstract: Disclosed herein is a magnetic powder which can provide a magnet having a high magnetic flux density and excellent magnetizability and reliability especially excellent heat resisting property (heat stability). The magnetic powder is composed of an alloy composition represented by Rx(Fe1-yCOy)100-x-z-wBzAlw (where R is at least one kind of rare-earth element, x is 8.1 - 9.4 at %, y is 0 - 0.30, z is 4.6 - 6.8 at %, and w is 0.02 - 1.

Abstract: Disclosed herein is a magnetic powder which can provide a bonded magnet having high mechanical strength and excellent magnetic properties. The magnetic powder has an alloy composition represented by the formula of Rx(Fe1-yCoy)100-x-zBz (where R is at least one rare-earth element, x is 10-15 at %, y is 0-0.30, and z is 4-10 at %), wherein the magnetic powder includes particles each of which is formed with a number of ridges or recesses on at least a part of the surface thereof. In this magnetic powder, it is preferable that when the mean particle size of the magnetic powder is defined by a&mgr;m, the average length of the ridges or recesses is equal to or greater than a/40 &mgr;m. Further, preferably, the ridges or recesses are arranged in roughly parallel with each other so as to have an average pitch of 0.5-100 &mgr;m.

Abstract: Disclosed herein is a magnetic powder which can provide magnets having excellent magnetic properties and having excellent reliability especially excellent heat stability. The magnetic powder is composed of an alloy composition represented by (R1-aDya)x(Fe1-bCob)100-x-yBy (where R is at least one kind of rare-earth element, x is 7.1-9.9 at %, y is 4.6-8.0 at %, a is 0.02-0.2, and b is 0-0.30), wherein the magnetic powder is constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, and the intrinsic coercive force (HCJ) of the magnetic powder at a room temperature is in the range of 400-750 kA/m.

Abstract: Disclosed herein is a method of manufacturing a magnetic material which can provide a bonded magnet having excellent magnetic properties and having excellent reliability. A melt spinning apparatus 1 is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and a cooling roll 5 having a circumferential surface 53 in which gas expelling grooves 54 are formed. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 6 so as to be collided with the circumferential surface 53 of the cooling roll 5, so that the molten alloy 6 is cooled and then solidified. In this process, gas is likely to enter between a puddle 7 of the molten alloy 6 and the circumferential surface 53, but such gas is expelled by means of the gas expelling grooves 54.

Abstract: Disclosed herein is a magnetic powder which can provide a bonded magnet having excellent magnetic properties and having excellent reliability especially excellent heat stability. The magnetic powder is composed of an alloy composition represented by Rx(Fe1−yCoy)100−x−z−wBzAlw (where R is at least one kind of rare-earth element, x is 7.1-9.9 at %, y is 0-0.30, z is 4.6-6.9 at %, and w is 0.02-1.5 at %), the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, wherein the magnetic powder has magnetic properties in which, when the magnetic powder is formed into an isotropic bonded magnet having a density &rgr; [Mg/m3] by mixing with a binding resin and then molding it, the maximum magnetic energy product (BH)max[kJ/m3] of the bonded magnet at the room temperature satisfies the relationship represented by the formula (BH)max/&rgr;2[×10−9 J·m3/g2]≧2.

Abstract: Disclosed herein is a magnetic powder which can provide a magnet having excellent magnetic properties and having excellent reliability especially excellent stability. The magnetic powder is composed of an alloy composition represented by Rx(Fe1-yCoy)100-x-z-wBzAlw (where R is at least one kind of rare-earth element, x is 7.1-9.9 at %, y is 0-0.30, z is 4.6-6.9 at %, and w is 0.02-1.5 at %), the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, wherein the magnetic powder has magnetic properties characterized in that, when the magnetic powder is formed into an isotropic bonded magnet having a density &rgr; [Mg/m3] by mixing with a binding resin and then molding it, the remanent magnetic flux density Br[T] at the room temperature satisfies the relationship represented by the formula of Br/&rgr; [×10−6T·m3/g]≧0.

Abstract: Disclosed herein is a magnetic powder which can provide a magnet having a high magnetic flux density and excellent magnetizability and reliability especially excellent heat resisting property (heat stability). The magnetic powder is composed of an alloy composition represented by Rx(Fe1−yCoy)100-x-z-wBzAlw (where R is at least one kind of rare-earth element, x is 8.1-9.4 at %, y is 0-0.30, z is 4.6-6.8 at %, and w is 0.02-1.

Abstract: A method of manufacturing magnetic powder is disclosed. This method can provide magnetic powder from which a bonded magnet having excellent magnetic properties and reliability can be manufactured. A melt spinning apparatus 1 is provided with a tube 2 having a nozzle 3 at the bottom thereof, a coil 4 for heating the tube and a cooling roll 5. The cooling roll 5 is constructed from a roll base 51 and a circumferential surface 53 in which gas flow passages 54 for expelling gas are formed. A melt spun ribbon 8 is formed by injecting the molten alloy 6 from the nozzle 3 so as to be collided with the circumferential surface 53 of the cooling roll 5, so that the molten alloy 6 is cooled and then solidified. In this process, gas is likely to enter between a puddle 7 of the molten alloy 6 and the circumferential surface 53, but such gas is expelled by means of the gas flow passages 54. The magnetic powder is obtained by milling thus formed melt spun ribbon 8.

Abstract: Disclosed herein is a magnetic powder which can provide a bonded magnet having excellent magnetic properties and having excellent reliability especially excellent heat stability. The magnetic powder is composed of an alloy composition represented by Rx(Fe1-yCoy)100-x-z-wBzAlw (where R is at least one kind of rare-earth element, x is 7.1-9.9 at %, y is 0-0.30, z is 4.6-6.9 at %, and w is 0.02-1.5 at %), the magnetic powder being constituted from a composite structure having a soft magnetic phase and a hard magnetic phase, wherein the magnetic powder has magnetic properties in which, when the magnetic powder is formed into an isotropic bonded magnet having a density &rgr; [Mg/m3] by mixing with a binding resin and then molding it, the maximum magnetic energy product (BH)max[kJ/m3] of the bonded magnet at the room temperature satisfies the relationship represented by the formula (BH)max/&rgr;2[×10−9 J·m3/g2]≧2.

Abstract: A magnet material having excellent magnetic properties and a bonded magnet formed of the magnet material as well as a method of manufacturing the magnet material are disclosed. The method of manufacturing the magnet material is carried out by discharging a molten metal of the magnet material from a nozzle while rotating a cooling roll having a surface layer composed of ceramics on its outer periphery to be collided with the surface layer of the cooling roll and solidified by cooling, the method of manufacturing the magnet material being characterized in that the time during which the magnet material is in contact with the surface layer of the cooling roll is not less than 0.5 ms when the molten metal of said magnet material is discharged from directly above the center of rotation of the cooling roll toward an apex part of the cooling roll to be collided with the apex part.