%A Shen Hua-Hai(申华海), Yu Hua-Jun(余华军), Fu Hao(付浩), Guo Yuan-Jun(郭袁俊), Fu Yong-Qing(傅永庆), and Zu Xiao-Tao(祖小涛) %T The effect of Si content on the martensitic transfor-mation temperature of Ni55.5e18Ga26.5–xSix alloys %0 Journal Article %D 2011 %J Chin. Phys. B %R 10.1088/1674-1056/20/4/046102 %P 46102-046102 %V 20 %N 4 %U {https://cpb.iphy.ac.cn/CN/abstract/article_112785.shtml} %8 2011-04-15 %X This paper investigates the effects of substitution of Si for Ga on the martensitic transformation behaviours in Ni--Fe--Ga alloys by  using optical metallographic microscope and differential scanning calorimetry (DSC) methods. The structure type of Ni$_{55.5}$Fe$_{18}$Ga$_{26.5  - x}$Si$_{x}$ alloys is determined by x-ray diffraction (XRD), and the XRD patterns show the microstructure of Ni--Fe--Ga--Si alloys transformed  from body-centred tetragonal martensite (with Si content $x = 0$) to body-centred cubic austenite (with $x = 2$) at room temperature. The  martensitic transformation temperatures of the Ni$_{55.5}$Fe$_{18}$Ga$_{26.5 - x}$Si$_{x}$ alloys decrease almost linearly with increasing Si  content in the Si content range of $x \le  3$. Thermal treatment also plays an important role on martensitic transformation temperatures in the Ni--Fe--Ga--Si alloy. The valence electronic concentrations, size factor, L2$_{1}$ degree of order and strength of parent phase influence the  martensitic transformation temperatures of the Ni--Fe--Ga--Si alloys. An understanding of the relationship between martensitic transformation  temperatures and Si content will be significant for designing an appropriate Ni--Fe--Ga--Si alloy for a specific application at a given  temperature.