Ti_3X相析出的电子浓度规律

ELECTRON CONCENTRATION RULE FOR THE FORMATION OF Ti_3X PHASE

在过去工作的基础上,进一步研究了 Ti-Al-Ge,Ti-Al-In,Ti-Al-Hf 及了 Ti-Al-Ta 四个三元系中 Ti_3X 相析出的电子浓度规律。实验结果表明,在含 Ge,In,Hf 及 Ta 的 Ti-Al 固溶体中,Ti_3X 相的形成仍遵循电子浓度规律,其特征电子浓度(?)=ΣNf_i=2.12。参与合金化的价电子是由合金元素的电子结构决定的,对于非过渡元素 In,Ge 的价电子数为 s+p 电子,即 N_(In)=3(s^2p^1),N_(Ge)e=4(s^2p^2),而过渡族元素 Hf 及 Ta 的价电子数是2,即 N_(Hf)=N_(Ta)=2。

Based on our previous works,four ternary alloy systems,Ti-Al-Ge,Ti-Al-In,Ti-Al-Hf and Ti-Al-Ta,were selected to investigate the electron concentrationrule for the formation of Ti_3X-phase.Results show that the formation of Ti_3X-phase in theTi-Al solid solution containing Ge,In,Hf and Ta obeys the electron concentration rule aswell.The characteristic electron concentration for the formation of Ti_3X-phase is(?)=∑ N_if_i=2.12.The valence electron number of the alloying elements depends on their ownelectronic structure,i.e.,N_(Ge)=4(s^2p^2),N_(In)=3(s^2p^1)for non-transition elements Ge and In;N_(Hf)=N_(Ta)=2 for transition elements Hf and Ta.