Dry Pressing and Isostatic Pressing Questions and Answers

Answer: C

The first two are correct and describe the trade the method makes. The third is the opposite of isostatic, which by definition applies equal pressure from every direction. The word itself records that there is no preferred axis.

Answer: D

Pressure vessels rated for high temperature and pressure are costly to buy and to run, and the cycle is slow. It is used where the last remnant of porosity genuinely matters, as in cutting tools and some medical implants.

Answer: A

Denser regions shrink less than looser ones, so the fired part warps or cracks along the boundary between them. Uniformity in the press is therefore a condition for dimensional accuracy after firing. Uniformity in the press is cheaper than correction afterwards.

Answer: B

Both are true and the reason traces the fault upstream: the kiln reveals the non-uniformity rather than creating it, so the remedy lies in the pressing operation rather than in the firing schedule. Kiln settings cannot correct a gradient built in at the press.

Answer: C

Correct answer: high enough to survive handling but low enough to crush

Spray-dried granules must survive transport, storage and flow into the die without breaking down into fines, which would ruin the flow and the fill. But they must then crush completely under the punch, because any granule surviving into the compact remains as a defect that sintering will not remove. Granule strength is therefore adjusted by binder content and type to sit between those two requirements.

Answer: D

Surviving granules leave inter-granule voids and boundaries that persist into the fired body as strength-limiting flaws. They must break down under pressure while remaining intact during handling. Granule strength is specified as a window rather than a minimum.