THE CALCULATION AND DETERMINATION FOR α_2 PHASE AND α_2/α_2+βPHASE BOUNDARY IN Ti_3AI BASED ALLOYS
LU Bin; LI Dong; CUI Yuyou (Institute of Metal Research; Chinese Academy of SCIencase; Shengyang 110015)(Manuscript received: 1994-11-07; in revised form 1995-06-05)
Cite this article:
LU Bin; LI Dong; CUI Yuyou (Institute of Metal Research; Chinese Academy of SCIencase; Shengyang 110015)(Manuscript received: 1994-11-07; in revised form 1995-06-05). THE CALCULATION AND DETERMINATION FOR α_2 PHASE AND α_2/α_2+βPHASE BOUNDARY IN Ti_3AI BASED ALLOYS. Acta Metall Sin, 1995, 31(21): 413-417.
Abstract The experimental results for three selected pseudoternary alloy systems (Ti3Al-Mo-Nb, Ti3Al-Nb-V and Ti3Al-Zr-V) show that the α2/α+β phase boundary obeys the electron concentration rule, and the valence electron number of the alloying elements depends on their own electronic structures. The valence electron for the transition elememts Ti, Zr, V, Mo, Nb, is s+d electron, i.e.NTi=Nzr=4(s2d2),Nv=5(s2d3), NNb=5(s1d4),Nmo=6(s1d5);the valence electron for the non-transition element Al is s+p electron, i.e.Nal=3(s2p1). The calculated model for a2 phase can be expressed as:N=ΣNifi,and the characteristic electron concentration for the α2/α+βphase boundary at 700℃may be expressed as .Nc=ΣNifi=3.787.Correspondent:(CUI Yuyou, Institule of Metal Research, Chinese Acadeiny of Sciences, Shenyang 110015)
CUI Yuyou;LI Dong;WAN Xiaojing Institute of Metal Research; Academia Sinica; Shenyang. OMEGA PHASE FORMATION IN Ti ALLOYS[J]. 金属学报, 1993, 29(2): 13-19.
