粉末注射成形烧结永磁铁氧体的脱脂工艺研究

摘要

采用粉末注射成形技术制备了烧结永磁锶铁氧体,并对其溶剂脱脂和热分解脱脂工艺进行初步研究.研究表明:溶剂温度越高,脱脂时间越长,黏合剂中可溶性组元的脱除率越高,溶剂B比溶剂A的脱脂效果更好.对60℃脱脂4h后的坯体进行热脱脂,升温速率为4℃/min,最高脱脂温度为480℃,此时脱脂缺陷最少,保形性最好,磁体的残余碳含量为0.0064wt%,大大低于国外报道的注射成形铁氧体的残余碳含量.注射成形烧结锶永磁铁氧体的密度为4.89g/cm3,剩余磁感应强度Br=0.398T,内禀矫顽力Hcj=236.8 kA/m,最大磁能积(BH)max=29.2 kJ/m3.%Powder injection molding technology was used for fabricating sintered Sr-ferrite permanent magnets.Solvent extraction and thermal debinding techniques were studied. The removal of the soluble binders increases with increasing debinding temperature and time. The debinding effect in solvent B was better than in solvent A. The sintered Sr-ferrite magnet with remanence of 398mT, coercive force of 236.8 kA/m and maximum energy product of 29.2 kJ/m3,was obtained by solvent extraction of 4 hours at 60℃ and thermal debinding with temperature rise rate of 4 ℃/min and the highest temperature of 480℃. In these conditions debinding defects were much less and the shape retention was better. The density of sintered magnet by PIM was 4.89 g/cm3. The content of residual carbon was 64 ppm, which was greatly lower than the level reported abroad.