Patent classifications
B22F3/087
Method for improving performance of sintered NdFeB magnets
The present disclosure relates generally to a method for improving the performance of sintered NdFeB magnet. A method of preparing a sintered NdFeB magnet therefore comprises the steps of: a) preparing alloy flakes from a raw material of the NdFeB magnet by a strip casting process; and b) preparing a coarse alloy powder from the alloy flakes by a hydrogen decrepitation process, the hydrogen decrepitation process including treatment of the alloy flakes under a hydrogen pressure of 0.10 MPa to 0.25 MPa for a duration of 1 to 3.5 hours, then degassing the hydrogen at a predetermined temperature between 300° C. to 400° C. for a duration time of 0.5 to 5 hours, and then mixing the resulting coarse alloy powder with a lubricant.
Method for improving performance of sintered NdFeB magnets
The present disclosure relates generally to a method for improving the performance of sintered NdFeB magnet. A method of preparing a sintered NdFeB magnet therefore comprises the steps of: a) preparing alloy flakes from a raw material of the NdFeB magnet by a strip casting process; and b) preparing a coarse alloy powder from the alloy flakes by a hydrogen decrepitation process, the hydrogen decrepitation process including treatment of the alloy flakes under a hydrogen pressure of 0.10 MPa to 0.25 MPa for a duration of 1 to 3.5 hours, then degassing the hydrogen at a predetermined temperature between 300° C. to 400° C. for a duration time of 0.5 to 5 hours, and then mixing the resulting coarse alloy powder with a lubricant.
Densification methods and apparatuses
An apparatus includes a first electrode exhibiting a first Seebeck coefficient, a second electrode exhibiting a second Seebeck coefficient greater than the first Seebeck coefficient, and particles between the first and second electrodes exhibiting a third Seebeck coefficient between the first and second Seebeck coefficients. An alternating current power supply is electrically connected to the first and second electrodes. Heat is generated due to the Peltier effect at a junction between the first electrode and the particles and at a junction between the second electrode and the particles. Heat is removed due to the Peltier effect at the junction between the first electrode and the particles and at the junction between the second electrode and the particles. The particles are densified due to heating and cooling phase transitions between a higher-temperature solid phase and a lower-temperature solid phase while compressing the particles.
Densification methods and apparatuses
An apparatus includes a first electrode exhibiting a first Seebeck coefficient, a second electrode exhibiting a second Seebeck coefficient greater than the first Seebeck coefficient, and particles between the first and second electrodes exhibiting a third Seebeck coefficient between the first and second Seebeck coefficients. An alternating current power supply is electrically connected to the first and second electrodes. Heat is generated due to the Peltier effect at a junction between the first electrode and the particles and at a junction between the second electrode and the particles. Heat is removed due to the Peltier effect at the junction between the first electrode and the particles and at the junction between the second electrode and the particles. The particles are densified due to heating and cooling phase transitions between a higher-temperature solid phase and a lower-temperature solid phase while compressing the particles.
Densification methods and apparatuses
An apparatus includes a first electrode exhibiting a first Seebeck coefficient, a second electrode exhibiting a second Seebeck coefficient greater than the first Seebeck coefficient, and particles between the first and second electrodes exhibiting a third Seebeck coefficient between the first and second Seebeck coefficients. An alternating current power supply is electrically connected to the first and second electrodes. Heat is generated due to the Peltier effect at a junction between the first electrode and the particles and at a junction between the second electrode and the particles. Heat is removed due to the Peltier effect at the junction between the first electrode and the particles and at the junction between the second electrode and the particles. The particles are densified due to heating and cooling phase transitions between a higher-temperature solid phase and a lower-temperature solid phase while compressing the particles.
EQUIPMENT AND METHOD FOR DEPOSITING PARTICLES USING LASER SHOCKWAVES
Equipment for selectively depositing, by shockwave-induced spraying, at least one particle on a deposition surface of a receiver substrate. The equipment including at least one laser source that emits a laser beam, a substrate carrier to which the substrate is fastened, a shockwave-generating layer having a first surface oriented toward the laser beam and a second surface oriented toward the deposition surface of the substrate, an optical system for directing and focusing the laser beam toward a focal region of the first surface. The second surface including a plurality of cavities, each cavity housing at least one particle. The laser beam generates a plasma in the focal region on the first surface and a shockwave that propagates within the generating layer from the first surface to the second surface in order to spray at least one particle in the direction of the deposition surface of the substrate.
EQUIPMENT AND METHOD FOR DEPOSITING PARTICLES USING LASER SHOCKWAVES
Equipment for selectively depositing, by shockwave-induced spraying, at least one particle on a deposition surface of a receiver substrate. The equipment including at least one laser source that emits a laser beam, a substrate carrier to which the substrate is fastened, a shockwave-generating layer having a first surface oriented toward the laser beam and a second surface oriented toward the deposition surface of the substrate, an optical system for directing and focusing the laser beam toward a focal region of the first surface. The second surface including a plurality of cavities, each cavity housing at least one particle. The laser beam generates a plasma in the focal region on the first surface and a shockwave that propagates within the generating layer from the first surface to the second surface in order to spray at least one particle in the direction of the deposition surface of the substrate.
EQUIPMENT AND METHOD FOR DEPOSITING PARTICLES USING LASER SHOCKWAVES
Equipment for selectively depositing, by shockwave-induced spraying, at least one particle on a deposition surface of a receiver substrate. The equipment including at least one laser source that emits a laser beam, a substrate carrier to which the substrate is fastened, a shockwave-generating layer having a first surface oriented toward the laser beam and a second surface oriented toward the deposition surface of the substrate, an optical system for directing and focusing the laser beam toward a focal region of the first surface. The second surface including a plurality of cavities, each cavity housing at least one particle. The laser beam generates a plasma in the focal region on the first surface and a shockwave that propagates within the generating layer from the first surface to the second surface in order to spray at least one particle in the direction of the deposition surface of the substrate.
COMPRESSION-MOLDING METHOD AND DEVICE FOR PERMANENT MAGNET
A compression-molding method for a permanent includes: providing a drive coil to generate an electromagnetic force when a transient current is passed into the drive coil, so as to apply a molding compression force to magnetic powder under compression, and providing an orientation coil to generate an orientation magnetic field when a transient current is passed into the orientation coil, thereby providing the magnetic powder under compression with an anisotropic property; and synchronously passing the transient currents to the drive coil and the orientation coil to synchronously generate the electromagnetic force and the orientation magnetic field, thereby completing compression-molding of the permanent magnet, wherein a magnitude of the electromagnetic force and an intensity of the orientation magnetic field are respectively changed by changing peak values of the transient currents.
COMPRESSION-MOLDING METHOD AND DEVICE FOR PERMANENT MAGNET
A compression-molding method for a permanent includes: providing a drive coil to generate an electromagnetic force when a transient current is passed into the drive coil, so as to apply a molding compression force to magnetic powder under compression, and providing an orientation coil to generate an orientation magnetic field when a transient current is passed into the orientation coil, thereby providing the magnetic powder under compression with an anisotropic property; and synchronously passing the transient currents to the drive coil and the orientation coil to synchronously generate the electromagnetic force and the orientation magnetic field, thereby completing compression-molding of the permanent magnet, wherein a magnitude of the electromagnetic force and an intensity of the orientation magnetic field are respectively changed by changing peak values of the transient currents.