| Popis: |
The applications for polymer-bonded magnets become increasingly important in our daily lives. One can find high performance bonded magnets in various electronic devices, office automation equipment, automotive components and home appliances such as computer hard disk drives (HDD), CDs, DVDs and sensors. Polymer-bonded magnets have some advantages compared to their sintered counterparts which include: (a) Cost effectiveness: Bonded magnets are made by net-shape or near net-shape manufacturing processes. Tight tolerances can be held without secondary or finish machining, significantly reducing the production cost; (b) Bonded magnets with complex geometries or magnet assemblies can be produced using multi-component injection molding techniques; (c) A broad selection of polymer binders and polymer additives gives the flexibility for production and meets the requirements of a variety of applications; (d) Isotropic bonded magnets can be easily magnetized into various and complex magnetization patterns; and (e) Fully automated production processes lead to more uniform magnetic properties, high precision and repeatability. Some disadvantages of polymer bonded magnets include: (a) Lower magnetic properties compared to their sintered counterparts due to polymer dilution effect; (b) The maximum operating temperature is limited by the temperature characteristics of polymers; and (c) Higher tooling cost for injection and extrusion molding processes. |
