A magnetic ink composition for three-dimensional (3D) printing a bonded magnet is provided. The magnetic ink composition includes magnetic particles, a polymer binder and a solvent. A 3D printing method for fabrication of a bonded magnet using the magnetic ink composition is also provided.

A bond magnet molding is provided that contains coated magnetic particles having at least two layers of an oxide layer of 1-20 nm on a surface of magnetic particles and an organic layer of 1-100 nm on an outer side of the oxide layer. The bond magnet molding preferably includes a Zn alloy as a binder. The Zn alloy has a strain rate sensitivity exponent (m value) of not less than 0.3 and an elongation at break of not less than 50%. The magnet particles have a nitrogen compound containing Sm and Fe that are solidified using the binder at a temperature not higher than a molding temperature.

Provided are a resin composition capable of providing a molded article excellent in magnetization, and a molded article formed from the resin composition. The resin composition for a bonded magnet contains from 10 to 90 parts by mass of a polyamide resin and from 90 to 10 parts by mass of a magnetic material. The polyamide resin contains a xylylenediamine-based polyamide resin. The xylylenediamine-based polyamide resin contains diamine-derived structural units and dicarboxylic acid-derived structural units. 70 mol % or more of the diamine-derived structural units are derived from a xylylenediamine. 70 mol % or more of the dicarboxylic acid-derived structural units are derived from an ?,?-linear aliphatic dicarboxylic acid having from 4 to 12 carbon atoms.

Disclosed are a soft bistable magnetic actuator, a fabrication method thereof, a fatigue testing device, and an auto underwater vehicle. The method for fabricating the soft bistable magnetic actuator includes the following operations: casting a soft precursor by injection molding, wherein the soft precursor consists of a soft deformable portion and a soft peripheral portion surrounded, the soft deformable portion is made of magnetic particles and polymer, and the soft peripheral portion is made of a magnetic particle, a mixture of organic liquid, and polymer; and extracting the organic liquid by an organic solvent shrinks the soft peripheral portion, buckles the soft deformable portion towards one side.

A method for manufacturing a permanent magnet includes preparing a plurality of permanent magnet blocks having the same size, spacing and arranging the plurality of permanent magnet blocks in a lower mold Having an opened upper side, pressing a side of the lower mold while circulating adhesive in the lower mold and integrating the plurality of permanent magnet blocks such that the adhesive is evenly applied to surface of each of the permanent magnet blocks, thereby forming a permanent magnet assembly and hardening the adhesive by heating the permanent magnet assembly.

Disclosed are a soft bistable magnetic actuator, a fatigue testing device, and an auto underwater vehicle. The soft bistable magnetic actuator includes a soft precursor. The soft precursor consisting of a soft deformable portion and a soft peripheral portion surrounded. The soft precursor is cast by injection molding, and the soft deformable portion is made of magnetic particles and polymer, and the soft peripheral portion is made of magnetic particles, a mixture of organic liquid and polymer, and the soft deformable portion is buckled by extracting the organic liquid by an organic solvent to shrink the soft peripheral portion.

A preform maintains shape retention properties and handling ability while suppressing deterioration in bonded magnet magnetic characteristics. A preform having an outer shell portion formed by binding a part of a magnet raw material of a mixture or kneaded product of magnet particles and a thermosetting resin that is powdery or granular, and an inner encapsulated portion formed of a remainder of the magnet raw material present inside the outer shell portion which maybe a portion in which the thermosetting resin has bound while still uncured. The inner encapsulated portion includes a powdery or granular magnet raw material. The preform is obtained by a preforming step of subjecting the magnet raw material to warm pressurization compacting, and maybe carried-out by setting a preforming temperature (Tp), which is the temperature of a preforming mold inner wall surface to be filled with magnet raw material, to tsTpts+20 C. (ts: thermosetting resin softening point).