A microscopic, branching crystal structure that grows into molten metal as it cools and solidifies. The primary arm shoots out first, followed by secondary and tertiary branches, driven by the direction of heat extraction. The size and spacing of these branches dictate the mechanical properties of the final casting, with finer structures generally yielding stronger metal.
We need a faster cooling rate in the mold to tighten up the dendrite spacing and improve the tensile strength.
Related terms
Microsegregation
The uneven distribution of alloying elements at the scale of individual crystalline grains.
Macrosegregation
Large-scale variations in chemical composition across a metal casting or ingot.
Chill
A metal insert placed in a sand mold to accelerate the cooling rate of a specific region of a casting.