Ni50Mn27Ga23快淬薄带的马氏体相变和磁感生应变

采用快淬技术制各了非化学计量成分的Ni50Mn27Ga23多晶薄带，对快淬薄带的马氏体相变和磁感生应变进行了研究。结果表明，快淬薄带侄冷却和加热过程中仍然发牛热弹性马氏体相变及逆相变，具有典型的热弹性形状记忆效应，并且比铸态合金具有更大的应变，但是马氏体相变温度下降。快淬工艺在合金内部引入特定的内应力，使薄带形成织构，是合金获得更大相变应变和磁感卞应变的原因。热处理后，内应力大大降低，导致磁感牛应变降低。

Martensitic Transformation and Magnetic-Field-Induced Strains in Ni50Mn27Ga23 Melt-Spun Ribbons

The non-stoichiometric Ni50Mn27Ga23 polycrystalline ribbons were prepared by melt-spinning technique. The martensitic transformation and the magnetic-field-induced strain of melt-spun ribbons were investigated. The experimental results show that the ribbons still undergo thermal-elastic martensitic transformation and reverse transformation in cooling and heating process. The melt-spun ribbons exhibit typical thermo-elastic shape memory effect and larger strain than as-cast specimens, but martensitic transformation temperature decreases. The reason which makes melt-spun ribbons have larger martensitic-transformation-strain and magnetic-fieldinduced strain is that the particular internal stress induced by melt-spinning makes a texture form in the melt-spun ribbons. That the internal stress is released strongly by heat treatment results in a decrease of the magnetic-field-induced strain.