Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Schematic model of the solidification of columnar grains with different crystallographic orientation. The dendrites of the middle grain change their growth direction of 90° at the melt pool boundary following the local thermal gradients (red arrow) resulting in a zig-zag shape similar to that observed in Figure 9b.
