利用片铸工艺制备了低稀土含量的钕铁硼合金铸片。对铸片显微特征进行表征，对比分析了不同厚度铸片的微观组织。发现厚度小于0.35mm时，铸片具有细小均匀的片状晶组织，无α-Fe产生；当厚度超过0.35mm，铸片的近自由端存在α-Fe树枝晶。调节辊轮线速度为2.5m/s时，获得了集中在0.2~0.35mm的厚度分布。通过添加低熔点晶界合金粉末，制得了具有较优显微结构和磁性能的低成本烧结稀土磁体。%Nd-Fe-B casting strips with low rare-earth content were prepared and characterized. The microstructure of the strips of different thickness was investigated. It was observed that when the thickness of casting strip was less than 0.35 mm, the formation ofα-Fe was effectively depressed and the columnar grains were fine, whileα-Fe dendrites were found in the free side of the strips thicker than 0.35mm. Optimized thickness distribution in the range of 0.2 to 0.35 mm, was acquired with a wheel speed of 2.5 m/s. By adding low-melting-point boundary alloy, sintered magnets with low-cost were produced with homogeneous microstructure and practical magnetic properties.
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