用温压法制备铁氧体

为了改进铁氧体磁性材料的成形性，拓宽其应用领域，研究了一种介于干压成形与热压铸成形之间的新的铁氧体成形工艺——温压成形。该成形方法将干压成形与热压铸成形有机结合，汲取各自的优点，克服了干压成形中压力不均匀、压坯内应力过大，热压铸成形中粘结剂过多、收缩率大、磁性能低的缺点。在温压成形过程中，只掺入少量粘结剂与添加剂，使其既能保证粉料良好的成形性与取向性，又能保证脱脂与烧结过程中不会产生过大的收缩与变形。结果表明，用该成形方法压制得到的压坯烧结性较好，可以得到90％以上的烧结相对密度。磁性能比热压铸磁体高很多，与干压磁场成形方法相当。该工艺能够适用于形状较为复杂并对磁性能有一定要求的中小型产品。

Warm compaction producing ferrite magnet

A new molding process for producing ferrite magnet-warm compaction was investigated in order to improve compactability and expand application field of ferrite materials. The warm compaction has both advantages of dry molding and hot pressing, meanwhile, it gets rid of some disadvantages of them. Compared with greens formed by dry molding, the greens formed by the warm compaction have better aspect and density uniformity, and less ejection force. Compared with greens formed by hot molding, the greens formed by the warm compaction have much less shrinkage while sintering, their shapes can be controlled more easily and magnetic properties are higher. The results show that the relative density of larger than 90% and magnetic properties better than that by hot pressing can be obtained by this process. This warm compaction can be used for producing ferrite parts with complex shape and middling magnetic properties.