Project ForgeManufacturing Engineering
Metal Casting
GATE 2018
Easy
During solidification of a pure molten metal, the grains in the casting near the mould wall are
- Acoarse and randomly oriented
- fine and randomly oriented
- Cfine and ordered
- Dcoarse and ordered
Explanation
At the mould wall, the metal is rapidly and uniformly chilled, nucleating many small grains simultaneously with no preferred growth direction — this forms the fine, randomly-oriented "chill zone," distinct from the columnar (ordered) grains that develop further from the wall.
Source: GATE ME 2018 Session 2 (Set 2) (2018)
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