TY - JOUR
T1 - Phase equilibria and stability of Heusler-type aluminides in the NiAl-Ni2AlTi-Ni2AlY (Y
T2 - V, Cr or Mn) systems
AU - Ishikawa, K.
AU - Ohnuma, I.
AU - Kainuma, R.
AU - Aoki, K.
AU - Ishida, K.
N1 - Funding Information:
This work was supported by the Grant-in-Aids for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan.
PY - 2004/3/24
Y1 - 2004/3/24
N2 - Phase equilibria between the B2 and L21 phases and critical boundaries of the B2/L21 continuous ordering in the NiAl-Ni 2AlTi-Ni2AlY (Y: V, Cr or Mn) concentration triangles were determined using diffusion couple technique in the temperature range of 1273-1573K. The B2+L21 two-phase region in the NiAl (B2)-Ni 2AlTi (L21) pseudo-binary section narrows and then disappears due to substitution of the Y element for Ti. The critical temperatures of the B2/L21 ordering at the stoichiometric Ni 2AlY, which were estimated from the experimental data on the basis of the Bragg-Williams-Gorsky approximation, decrease linearly with increasing average of the 3d+4s electron concentration of the elements occupying the Y site. Furthermore, the critical composition boundary of the B2/L21 ordering in the concentration triangle was also well described by the electron concentration of the Y atoms. It can be concluded that the electron concentration of the Y site atoms strongly influences the stability of the Ni2AlY Heusler phase.
AB - Phase equilibria between the B2 and L21 phases and critical boundaries of the B2/L21 continuous ordering in the NiAl-Ni 2AlTi-Ni2AlY (Y: V, Cr or Mn) concentration triangles were determined using diffusion couple technique in the temperature range of 1273-1573K. The B2+L21 two-phase region in the NiAl (B2)-Ni 2AlTi (L21) pseudo-binary section narrows and then disappears due to substitution of the Y element for Ti. The critical temperatures of the B2/L21 ordering at the stoichiometric Ni 2AlY, which were estimated from the experimental data on the basis of the Bragg-Williams-Gorsky approximation, decrease linearly with increasing average of the 3d+4s electron concentration of the elements occupying the Y site. Furthermore, the critical composition boundary of the B2/L21 ordering in the concentration triangle was also well described by the electron concentration of the Y atoms. It can be concluded that the electron concentration of the Y site atoms strongly influences the stability of the Ni2AlY Heusler phase.
KW - Heusler alloys
KW - Order-disorder transition
KW - Phase equilibria
KW - Phase stability
UR - http://www.scopus.com/inward/record.url?scp=1442310578&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1442310578&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2003.08.002
DO - 10.1016/j.jallcom.2003.08.002
M3 - Article
AN - SCOPUS:1442310578
VL - 367
SP - 2
EP - 9
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
IS - 1-2
ER -