中文摘要：

采用X射线衍射仪（XRD）、扫描电子显微镜（SEM）及高分辨率透射电子显微镜（HRTEM）对Cu-3Ti-5Ni合金深冷处理前后的组织演化及析出相进行了表征分析,采用维氏硬度计、涡流电导仪分别分析了深冷处理对合金硬度和导电率的影响。结果表明,Cu-3Ti-5Ni合金经深冷处理后,析出细小颗粒相,Ni3Ti第二相析出更完全。TEM分析发现深冷处理后针状Ni3Ti析出相的周围出现了位错的缠绕,基体中的位错线向位错环转换。适当时间的深冷处理可有效提高Cu-3Ti-5Ni合金的硬度,经深冷处理15 h后合金硬度达最大值217 HV10,但深冷处理对合金导电率的影响甚微。

英文摘要：

The microstructural evolution and precipitated phase of Cu-3Ti-5Ni alloy before and after cryogenic treatment were characterized by means of X-ray diffractometer（ XRD）,scanning electron microscope（ SEM） and high resolution transmission electron microscope（ HRTEM）,and the effect of cryogenic treatment on the hardness and electrical conductivity was investigated by Vickers hardness tester and eddy-current conductivity device respectively.The results show that Cu-3Ti-5Ni alloy after cryogenic treatment precipitates fine particles phase and precipitates Ni3 Ti phase more completely.The TEM analysis shows that the intertwining of dislocation presents around the Ni3 Ti precipitate and the dislocation lines transform into dislocation loop in the Cu matrix.The cryogenic treatment with appropriate time can effectively improve the hardness of Cu-3Ti-5Ni alloy and the hardness of the alloy reaches up to the peak value of 217 HV10 after cryogenic treatment for15 h,while the cryogenic treatment has little effect on the electrical conductivity of the alloy.