中文摘要：

通过向Ti50Ni50合金中加入Fe和Nb元素，制备出一种四元Ti49Ni50-xFexNb1形状记忆合金。采用X射线衍射和背散射电子衍射的方法，测试和分析了合金的相结构及微观组织形态，采用电阻法系统研究了合金的相变特性。结果表明：Nb元素的加入并没有改变TiNiFe合金的B2结构，仅导致了极少量的富Nb相在基体中析出。但是Nb元素的加入抑制了合金相变过程中R相的产生；随着Fe元素原子分数从1％提高到3％，合金的马氏体相变开始温度从273．7K急剧降低至137．2K。另外，Ti49Ni47Fe3Nb1形状记忆合金表现出良好的形状记忆效应。当预应变为8％时，合金的应变回复率达到了92．66％。

英文摘要：

A series of quaternary shape memory alloysTi49Ni50-xFexNb1 （at%） are prepared by adding elements Fe and Nb into alloys Ti50Ni50. The microstructure morphology and phase transition behavior of these alloys are studied systematically by X-ray diffraction, backscattered electron and electrical resistance measurements. It is shown that the addition of Nb does not change the phase structure of alloy TiNiFe （B2） and it just causes a tiny quantity of Nb-rich phase to precipitate in the matrix. However, the Nb addition inhibits the appearance of the R-phase in the process of phase transformation. With the increase of Fe content from 1 at% to 3 at%, the martensitic transformation temperature decreases rapidly from 273.7 K to 137.2 K. In addition,shape memory alloys Ti,9 Ni47 Fe3Nb1 exhibites good shape memory effect and its strain recovery rate reaches 92.66 % after a pre-strain of 8 %.