Acta Metallurgica Sinica (English Letters) ›› 1989, Vol. 2 ›› Issue (1): 69-72.

• Research paper • Previous Articles     Next Articles

PHASE BOUNDARY OF α_2 PRECIPITATION IN Ti-Al-La TERNARY SYSTEM

YA NG Rui LI Dong WAN Xiaojing Institute of Metal Research,Academia Sinica,Shenyang,China   

  • Received:1989-02-25 Revised:1989-02-25 Online:1989-02-25 Published:2009-10-10

Abstract: The phase boundary,of α_2 precipitation at 600℃ in Ti-AI-La ternary system has been de- termined by TEM examination,which shows three kinds of phase regions,namely the single α phase region,the transitional phase region where there is superlattice reflection but no α_2 precipitation,and the α+α_2 region.A point of maximum aluminium content was found to exist on the α/(α+α_2)boundary and the track of the boundary was explained in terms of the internal oxidation of lanthanum and the electron concentration rule for α_2 formation.

Key words: ternary system Ti-Al-La, phase boundary, α_2 precipitation, internal oxidation, electron concentration