Tg of bands or PLC bands. So, the work hardening capacity of AIMg6.5 alloy is reduced due to the 
ta Ptüperties inhomogeneous deformation at room temperature (£pom<M). 
v au ling Fig.2 illustrates the position of fracture surfaces in respect to the tensile axis for thinner sample with 
“a Tab high w/f ratio (w/t=8.3) and for thicker sample with low w/f ratio (w/t=2.8). 
ned, py 
“18 reduction 
) Rerystallizeg 
lat is Cased by 
Ste Hall-Pegh 
63 | fl 
1809 18: 
HY 
Fig.2: The position of fracture surfaces on the tension specimen with: a, b) fine-grained fully 
recrystallized structure (w/t=8.3); c, d) coarse-grained non-fully recrystallized structure (w/r=2.8). 
AIMg6.5 alloy 
3m temperature 
racterized by On the thinner specimens with fine-grained fully recrystallized structure and high w/t ratio, 
is induced by w/t=6.3+8.3 (Fig.2a), the failure occurs along the plane which is inclined at ~60-70° to the tensile 
a It was also direction. The fracture surface was almost parallel to the PLC bands, which are clearly visible on 
he tested allo that specimen surface, and oriented at £60° to the tensile axis (on the broad specimen face, Fig.2b). 
vas eminated As the plastic strain ratio in the tested material was about R~0.55 in the rolling direction [10], the 
st beyond the angle of localized necking, according to the Hill’s theory [12], should be about 6~59°. It means that 
wtead in other the PLC bands make a regions of localized necks, and later at these places the fracture appearance is 
content [6-9 favorized. In the case of thicker sample with coarse-grained non-fully recrystallized structure and 
ıtween uniform low w/t ratio, w/f=2.5+5 (Fig.2c,d), PLC bands are less evident and the failure occurs at ~55° 
ei) and work through the specimen thickness (Fig.2c) at an orientation of 90° to the tensile axis on the broad 
tested M63 specimen face (Fig.2d). However, having in mind that the appearance of PLC bands was suppressed 
e uniform sin in coarse-grained samples (Fig.2d), it was assumed that there were no places of strain localization, 
dos] parallel to PLC bands, but the fracture surface corresponds to localized shear banding in the planes 
a te pod with maximum shear stress through thickness. A fractographic study of AIMg6.5 tensile specimens 
m due fo neck using scanning electron microscope (SEM) has shown transgranular ductile dimple fracture (Fig.3). 
fond 85 18 
maximum load. 
iy parameters 
try (Fig.]) The 
zo found rather 
value of 031 
structure it Was 
ed that negative 
also causes the 
ag shear failure 
at. within. Shear Fig.3: SEM fractographs of AlMg6.5 tension specimens with a) coarse-grained non fully 
recrystallized structure (w//2.8) and b) fine grained fully recrystallized structure (w//=8.3). 
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