Casting Shrinkage — Contraction from Liquid to Solid Among the following alloys/metals, which exhibits the greatest volumetric shrinkage during solidification from the molten state?

Introduction / Context:
Solidification shrinkage affects riser design, feeding, and the likelihood of internal cavities in castings. Different alloys shrink by different amounts between liquid and solid states, and some (like graphitic cast irons) can even show apparent expansion due to graphite precipitation.

Given Data / Assumptions:

• Comparison across cast steel, cast iron, brass, and Admiralty metal.
• Typical foundry compositions, not exotic low-shrinkage special alloys.
• Gray cast iron behavior dominated by graphite expansion effects.

Concept / Approach:
Steels generally show considerable solidification shrinkage and require generous feeding with properly designed risers. Gray cast irons often have lower net shrinkage and can even offset shrinkage via graphite precipitation. Copper-zinc brasses and Admiralty metal have moderate shrinkage, typically less than carbon steels. Therefore, among the listed options, cast steel exhibits the greatest contraction from liquid to solid.

Step-by-Step Solution:
Recall relative trends: steel > brass/admiralty > gray iron (often lowest).Consider graphite expansion in cast iron reducing effective shrinkage.Select cast steel as the highest-shrinkage case from the list.

Verification / Alternative check:
Foundry design references prescribe larger risers and stricter feeding for steel castings than for gray irons or common brasses, reflecting higher shrinkage.

Why Other Options Are Wrong:
Cast iron: graphite formation mitigates shrinkage; in some grades apparent expansion occurs.Brass/Admiralty: intermediate shrinkage, generally below steels.“Gray iron with high graphite expansion”: explicitly indicates low net shrinkage.

Common Pitfalls:
Treating all irons the same; white irons behave differently but gray irons commonly offset shrinkage.

Final Answer:
Cast steel