The GATE Grind

GATE 2019 ME (ME2) – Question 25

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

Fluidity of molten cast alloys, without flux addition, increases with increased ______.

  1. viscosity
  2. surface tension
  3. freezing range
  4. degree of superheat

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Show answer and explanation

Correct answer: (D) degree of superheat

Explanation

Increasing superheat raises the initial liquid temperature above its melting range,so more heat must be lost before freezing interrupts flow. This lets the metal travel farther and fill thinner sections. **Degree of superheat,D** increases fluidity;greater viscosity resists flow.