摘要
采用自制的高梯度定向凝固装置制备了晶粒取向的稀土超磁致伸缩材料并考察了定向凝固和热处理工艺参数对材料组织、性能的影响规律。在本实验工艺条件下（定向温度１３７０℃），抽拉速度１２ｍｍ／ｍｉｎ，热处理温度９５０℃，保温６ｈ，炉冷），材料的磁致伸缩值可达到１８００ｐｐｍ（压应力１２．５ＭＰａ）。组织分析表明，定向凝固使得材料沿凝固方向形成了［１１０］取向组织从而使磁致伸缩值明显提高，而热处理对性能的进一步提高则很可能是通过消除内应力或促进元素均匀分布而实现的。
Grain aligned rare earth giant magneto strictive materials were prepared using a high gradient directional solidification apparatus made by ourselves.The effects of processing parameters in directional solidification and heat treatment on the microstructure and magnetostriction were investigated.Magnetostriction(λ=1800ppm) was obtained in samples prepared under the optimum conditions in which alloys were melted at 1370℃,directionally solidified at the drawing rate of 12mm/min,heat treated at 950℃ for 6h,and then furnace cooled.Microstructural studies revealed that a preferred orientation was developed in materials during the directional solidification,which resulted in the enhancement of magnetostriction.Further improvements in the magnetostriction by heat treatment arose probably from the elimination of the internal stress in materials or the more homogeneous distribution of the elements.
出处
《功能材料》
EI
CAS
CSCD
1996年第6期502-505,共4页
Journal of Functional Materials
关键词
稀土
磁致伸缩
定向凝固
磁性材料
rare earth,magnetostriction,directional,solidification
