Shape Memory Effect of Sputtered Ni-rich Ni2MnGa Alloy Films Aged in Constraint Condition
Shape Memory Effect of Sputtered Ni-rich Ni2MnGa Alloy Films Aged in Constraint Condition
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溅射富镍Ni2MnGa合金薄膜约束时效的形状记忆效应
DOI：
10.2320/matertrans.42.1886
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发表时间：
2001
影响因子：
1.2
通讯作者：
K. Itagaki
中科院分区：
文献类型：
--
作者：
Shinji Isokawa;Motohiko Suzuki;M. Ohtsuka;M. Matsumoto;K. Itagaki
金属间化合物Ni2MnGa具有形状记忆效应和铁磁性。这种化合物的薄膜可用于微型机械的致动器。利用射频磁控溅射装置，以Ni52Mn24Ga24靶材，在Al_2O_3衬底上制备了厚度接近5μm的富镍Ni2MnGa薄膜。溅射功率为400W，衬底温度由冷却水控制在323K。沉积膜的组成为：Ni-23.4mol%Mn-23.0mol%Ga。它们在1073K下进行36K的均匀化和有序化处理，然后在炉中缓慢冷却。用差示扫描量热仪测量了薄膜的马氏体相变温度，结果为：M S=315K，Mf=311K，As=316K，Af=321K。为了产生形状记忆效应，在573~773K的温度范围内，在一定的约束条件下时效0.9~3.6K。通过热循环实验发现，它们具有双向形状记忆效应。
The intermetallic compound Ni2MnGa has a shape memory effect and a ferromagnetic property. Films of this compound may be applied for an actuator of micro-machines. The Ni-rich Ni2MnGa films with a nearly 5 μm thickness were deposited on an Al 2 O 3 substrate by a radio-frequency magnetron sputtering apparatus with a Ni 52 Mn 24 Ga 24 target. The sputtering power was 400 W and the substrate temperature was kept at 323 K by cooling water. The composition of the deposited films was Ni-23.4 mol%Mn-23.0 mol%Ga. They were annealed at 1073 K for 36 ks for homogenization and ordering, and slowly cooled down in the furnace. Martensitic transformation temperatures of the films were measured by a differential scanning calorimeter, and the results were M s = 315 K, M f = 311 K, As = 316 K and A f = 321 K. To induce a shape memory effect, the annealed films were aged at 573-773 K for 0.9-3.6 ks in a constrained condition. It was found that they showed the two-way shape memory effect by thermal cycling.