Development of new shape memory alloys-Alloy design and process-

Ni-Fe-Ga合金和Ni-Fe-Ga-Co合金作为铁磁形状记忆合金和高温合金受到了广泛的关注。本研究采用微下拉法制备了这两种合金的纤维状单晶。研究了晶体生长的最佳条件、晶体的凝固行为和物理性能。结果表明，在10 mm/min的提拉速率下，可以生长出直径约1-3 mm、长度约200 mm的单晶丝。它们的有效分配系数约为1，表明宏观偏析很小.应力-温度相图表明，马氏体相变行为符合Clausius-Clapeyron关系。

Ni-Fe-Ga alloys and Ni-Fe-Ga-Co alloys have been received great attention as ferromagnetic shape memory alloys and high temperature alloys. In this study, the fiber shape single crystals of these alloys were prepared by the micro-pulling-down method. Optimum conditions for the crystal growth and the solidification behavior and physical properties of them were investigated. As the results, the single crystal wires approximately 1-3 mm in diameter and 200 mm in length could be grown by 10 mm/min. pulling-down-rate. The effective distribution coefficient of them approximately unit, suggesting that the macroscopic segregation are very small. The stresstemperature phase diagram shows that the martensitic phase transformation behavior showed the Clausius-Clapeyron relation.