elastic anisotropy of hcp metal crystals and polycrystals

IJRRAS 6 (4) ● March 2011 Tromans ● Elastic Anisotropy of Hcp Metal Crystals and Polycrystals
(a) E data
Cd
(a) E data
Zn
0.5
0.5
Mg
Y
Be
Zr
X3
0
X3
0
1.0
0.5
0.5
1.0
1.0
0.5
0.5
1.0
0.5
0.5
Co
Mg
Cd
Zn
Be
Ti
Ti
Y
Co
Zr
473
(b) G data
(b) G data
(a) (b)
Figure 9. Normalized polar diagrams: Mg, Cd, Zn, Be (top) and Ti, Y, Co Zr (bottom). (a) E data: (b) G data.
It is evident that anisotropy in the normalized behaviour of Cd and Zn is extreme for both E and G, whereas
Mg and Be approach a distorted circular symmetry. In the Ti, Y, Co and Zr group, Y exhibits the least anisotropy
whereas Ti, Co and Zr have significant departures from circularity of E in the X3 direction. The anisotropic
behaviour of G behaviour is similar for Y, Co and Zr with Ti exhibiting a larger anisotropy in the X3 direction.
Figure 10 shows the modulus behaviour of Nd, Sc, Lu and La, Re and Er. The approximate circular nature of the
polar diagrams of E and G for Lu indicate it is almost isotropic in contrast to Nd and Sc which exhibit distorted
circles in the X3 direction. Regarding La, Re and Er, all three show distorted circular symmetry in their E-behaviour.
However, in the case of their G-behaviour, Er approaches circular symmetry more closely.
Cd
0.5
0.5
Zn
Be
Mg
X3
0
X3
0
1.0
0.5
0.5
1.0
0.5
0.5
Ti
0.5
0.5
Co
Mg
Cd
Be
Zn
Ti
Y
Co
Zr