Fig. 5—(a) Optical micrograph of high-Si FZ showing (i) inclusions
decorating columnar grain boundaries and (ii) inclusions in the equiaxed
zone. (b) Inclusions in the weld center zone of high-Si weld,
showing a lower density and random distribution in comparison to
columnar grain zones. (c) Inclusions in the weld center zone of high-
Al weld, showing a coarse and more dense distribution compared
with the high-Si steel weld centerline