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GATE 2019 ME (ME1) – Question 47

Casting, Forming and Joining Processes · Casting: patterns, moulds, cores, solidification, riser and gating design, defects · 2 marks · Multiple choice

Match casting defects P: blow hole, Q: misrun, R: hot tearing, S: wash with causes 1: poor collapsibility, 2: mould erosion, 3: poor permeability, 4: insufficient fluidity.

  1. P-4, Q-3, R-1, S-2
  2. P-3, Q-4, R-2, S-1
  3. P-2, Q-4, R-1, S-3
  4. P-3, Q-4, R-1, S-2

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Correct answer: (D) P-3, Q-4, R-1, S-2

Explanation

Blowholes follow trapped gas from poor permeability(P3). Misruns arise when fluidity is insufficient to fill the cavity(Q4). Hot tearing results when a shrinking casting is restrained by poor mould collapsibility(R1). Wash is mould erosion(S2). Thus **P3,Q4,R1,S2,D**.