Fig.6. OM images showing the microstructures of ter-crystal samples with different withdrawal speeds of Exp.3-1 (a~d) and Exp.3-2 (e~h) (White triangles: the blocking of the favorably aligned dendrites; black triangles: the blocking of the unfavorably aligned dendrites; white arrows: the branching of the favorably aligned dendrites; black arrows: the branching of the unfavorably aligned dendrites) (a, e) longitudinal section (b, f) 90 mm transverse section (c, g) 55 mm transverse section (d, h) 10 mm transverse section
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