* 7% 200pm | 200 pm 
orem Frommer 
Fig. 6: Effect of the cooling rate on the dendrite morphology, v = 2x 10* and 5x10” m/s 
During the measurements the primary arms were selected in the photos. Their edges were drawn 
around and after multiple image transformation (binary edit, binary logical, copy invert, binary 
identification, edgefeat and fill holes) the area of the arms (Fig.7.a.) was measured of which arm 
spacing (A,) could be calculated [3]. The tertiary dendrite arm spacing();) and the secondary 
dendrite arm spacing (A) (Fig. 7.b, 7.c) were measured along a line drawn in the picture [4]. The 
measuring process is presented in Fig. 8. 
) 
Eutectic 
(atALCu) 
f | 
L * 
<> J ! 
TERA 
Rad 
n ee 
oe 
Eutectic 
a 
a 
b.. 
32