The six-jump diffusion cycles in B2-compounds

被引:2
作者
Drautz, R [1 ]
Meyer, B [1 ]
Fähnle, M [1 ]
机构
[1] Max Planck Inst Met Res, DE-70569 Stuttgart, Germany
来源
DIFFUSIONS IN MATERIALS: DIMAT2000, PTS 1 & 2 | 2001年 / 194-1卷
关键词
B2-NiAl; self-diffusion in intermetallic compounds; six-jump-cycle;
D O I
10.4028/www.scientific.net/DDF.194-199.417
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The self-diffusion in B2 compounds AB via six jump cycles is investigated by using elementary properties of stochastic processes. The ratios D-A/D-B of the self-diffusion coefficients for the two components and P-110/P-100 of the probabilities for effective jumps via 110 or 100 cycles have been derived by Arita et al. for an idealized six jump model where the energetics is assumed to be the same for all three geometrically different six jump cycles in the B2 structure. Based on these limits the experimental ratios often have been used to explore whether self-diffusion via six jump cycles is in principle relevant for the special investigated B2 compounds. In contrast, we will show that the limits for D-A/D-B are at least considerably widened and that for P-110/P-100 no limits at all can be established when abandoning the unrealistic assumptions of the idealized model. It is demonstrated by ab-initio density functional calculations for NiAl that strong deviations from the idealized model are probably the rule and not the exception.
引用
收藏
页码:417 / 422
页数:6
相关论文
共 16 条
[1]   DIFFUSION MECHANISMS IN ORDERED ALLOYS - A DETAILED ANALYSIS OF 6-JUMP VACANCY CYCLE IN THE B2 TYPE LATTICE [J].
ARITA, M ;
KOIWA, M ;
ISHIOKA, S .
ACTA METALLURGICA, 1989, 37 (05) :1363-1374
[2]  
BORNSEN N, IN PRESS J ALLOYS CO
[3]   The six-jump diffusion cycles in B2 compounds revisited [J].
Drautz, R ;
Fähnle, M .
ACTA MATERIALIA, 1999, 47 (08) :2437-2447
[4]   Diffusion in intermetallic phases of the Fe-Al system [J].
Eggersmann, M ;
Mehrer, H .
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, 2000, 80 (05) :1219-1244
[5]   VACANCY DIFFUSION IN BINARY ORDERED ALLOYS [J].
ELCOCK, EW ;
MCCOMBIE, CW .
PHYSICAL REVIEW, 1958, 109 (02) :605-606
[6]   Diffusion in metals and intermetallic compounds: The impact of ab-initio calculations [J].
Fahnle, M ;
Meyer, B ;
Mayer, J ;
Oehrens, JS ;
Bester, G .
DIFFUSION MECHANISMS IN CRYSTALLINE MATERIALS, 1998, 527 :23-34
[7]   Theory of atomic defects and diffusion in ordered compounds, and application to B2-FeAl [J].
Fähnle, M ;
Mayer, J ;
Meyer, B .
INTERMETALLICS, 1999, 7 (3-4) :315-323
[8]   DIFFUSION-COEFFICIENT IN CRYSTALS WITH MULTIPLE JUMP FREQUENCIES [J].
ISHIOKA, S ;
KOIWA, M .
PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES, 1985, 52 (02) :267-277
[9]  
MAYER J, 1997, DEFECT DIFFUS FORUM, V143, P285
[10]  
MEHRER H, 1996, DIFFUSION INTERMETAL, V37, P1259