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GATE 2023 ME – Question 25

Casting, Forming and Joining Processes · Casting: patterns, moulds, cores, solidification, riser and gating design, defects · 1 mark · Multiple select

In a metal casting process to manufacture parts, both patterns and moulds provide shape by dictating where the material should or should not go. Which of the option(s) given correctly describe(s) the mould and the pattern?

  1. Mould walls indicate boundaries within which the molten part material is allowed, while pattern walls indicate boundaries of regions where mould material is not allowed.
  2. Moulds can be used to make patterns.
  3. Pattern walls indicate boundaries within which the molten part material is allowed, while mould walls indicate boundaries of regions where mould material is not allowed.
  4. Patterns can be used to make moulds.

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Show answer and explanation

Correct answer: (A) Mould walls indicate boundaries within which the molten part material is allowed, while pattern walls indicate boundaries of regions where mould material is not allowed.; (B) Moulds can be used to make patterns.; (D) Patterns can be used to make moulds.

Explanation

The mould cavity is the space the molten metal fills, so the mould walls bound the region where the part material is allowed (A is correct and C has this the wrong way round). The pattern is a replica of the part around which the mould is packed, so the pattern walls mark where the mould material may not go. A pattern is used to make a mould (D). A mould can also be used to make patterns, for example wax patterns for investment casting are cast in a metal mould (B).