中文摘要：

用X射线衍射、金相观察、电子探针、透射电镜和磁性测量研究了Gd2Co17-χAlχ（χ≤5）合金的微结构、相组成、相成分和热磁特性。结果表明，在1173和1323K退火的χ≤3的样品和在1323K退火的χ=4的样品近似为单相，2：17主相仅含Gd、Co、Al 3种元素，具有菱方Th2Zn17型结构，少量ζ杂质相是富Gd氧化物、富Co相或ζ-CoAl相；在1173K退火的χ=4的样品含有较多的第二相，它是具有六方CaCu5型结构的1：5相；χ=5的退火样品是三相，主相是1：5相，第二相和第三相分别是2：17相和具有CsCl结构的ζ-CoAl相，提高退火温度，样品的2：17相含量增多，1：5相相应减少；在室温以下，样品（χ≤4）的自发磁化强度随温度降低而减小，在74和65K附近，χ=4的两相样品和单相样品的自发磁化强度M0先后降为零，但χ=5的样品磁距随温度降低而增大。

英文摘要：

The microstructure, phase constituent and compositions and thermal magnetic behavior of Gd2Co17-χAlχ（χ≤5） alloys have been studied by means of the X-ray diffraction, metallographic examination, electron probe microanalysis and transmission electron microscopy. Results show that the samples with χ≤3 annealed at 1173K and 1323K and the sample with χ=4 annealed at 1323K are approximately single phase, 2：17 main phase with rhombohedral Th2Zn17-type structure only containing Gd, Co and Al elements, while the small amount of impurity phases being the oxide of rich-Gd, Co-rich phase or ζ-CoAl. The sample with χ=4 annealed at 1173K has quite a lot of the 1：5 second phase with CaCu5-type structure. The sample with χ=5, as expected, was multi-phase, and its main phase was 1：5 and the second and third phase are 2：17 phase and ζ-CoAl with CsCl-type structure, respectively. Increasing annealing-temperature is in favour of the formation of 2：17 phase and the reduction of the 1：5 phase. Below the room-temperature, the spontaneous magnetization of annealed samples （χ≤4） reduces with decreasing the temperature. The value of Mo reduces to zero at about 74K and 65K, respectively, for the double-phase and single-phase samples with χ=4. But the moment of the annealed sample with χ=5 increases as decreasing the temperature.