【摘要】 研究了成分为Ｔｂ０３Ｄｙ０７（Ｆｅ１－ｘＭｘ）１９５（Ｍ＝Ｍｎ，Ａｌ，Ｔｉ，Ｂ，ｘ＝００３）的合金在高温度梯度区熔定向凝固过程中的结晶形貌与晶体生长速度ｖ，温度梯度ＧＬ之间的关系。发现当温度梯度一定时，随结晶速度增加，结晶形貌由平面晶向胞状晶、胞枝状晶和树枝晶转变。合金的结晶速度为一定时，随温度梯度ＧＬ由低向高变化，合金由发达的树枝晶向胞枝状晶和胞状晶转变。当合金具有胞枝状晶形貌时，＜１１２＞沿棒状样品的轴向取向，此时合金可获得优异的磁致伸缩性能。更多还原

【Abstract】 The relationships between the crystal morphologies and crystal growth rate v and temperature gradient GL for the alloys with composition of Tb0.3Dy0.7(Fe1-xMx)1.95(M=Mn,Al,Ti,B,x=0.03) prepared by zone melting directional solidification have been studied. It was found that when the temperature gradient GL with a certain value, as increasing in crystal growth rate v, the crystal morphologies of alloys changes from planar to cellular, cellular dendrite and finally the developed dendrite. When the crystal growth velocity v is a value fixed, with increase of GL, the crystal morphologies change from developed dendrite to cellular dendrite and cellular. The samples with cellular dendrite possess <112> axial orientation and optimum magnaetostrictive properties.更多还原