Powder Metallurgy - Chapter 15 Review

Fill-in-the-blank practice flashcards covering fundamental powder metallurgy principles, processes, formulas, tooling classes, and product design rules from Chapter 15.

The four core steps of the conventional powder metallurgy processing sequence in order are characterize, produce, __________, and sinter + finish.

press

A major economic advantage of the press and sinter PM process is high material utilization, where about __________ of the starting material becomes product.

$$97\%$$

According to the ideal particle shape classification in powder metallurgy, needle-like particles are described as __________ particles.

acicular

In powder characterization, the attribute that determines the required fill volume in a die is __________ density.

apparent

In metallic powder production by __________, a molten liquid stream is broken into droplets by a high-velocity gas or liquid jet before solidifying.

atomization

The three sequential mechanical actions during conventional compaction in a die are fill, press, and __________.

eject

Compaction pressures typically range from about $70\,\text{MPa}$ for aluminum up to about __________ for iron and steel.

$$700\,\text{MPa}$$

To determine the required press force $F$ in a powdered metal press using $F = A \times P$, the parameter $A$ represents the __________ area perpendicular to the pressing direction.

projected

Class II PM parts consist of simple but thicker shapes that require pressing from __________ directions.

two

In a continuous sintering furnace, the stage where additives and lubricants are burned off before reaching full sintering temperature is the __________ stage.

preheat

Solid-state sintering of metal powders typically takes place at approximately __________ to $0.9$ of the metal's absolute melting temperature.

$$0.7$$

During particle bonding in sintering, contact points between powder particles grow into __________ before pore volume shrinks and grain boundaries form.

necks

In Cold Isostatic Pressing (CIP), powders are sealed inside a flexible mold made of __________ and compacted by hydrostatic pressure.

rubber

The secondary operation in powder metallurgy where oil or other fluid is soaked into the pores of a sintered part is called __________.

impregnation

In PM economics, the formula for total unit cost is $C_{pc} = C_m + C_{pc1} + C_{pc2} + C_{pc3}$, where $C_{pc3}$ represents the __________ cost per piece.

sintering

Features such as side holes and __________ must be avoided in direct PM press design because they prevent straight vertical ejection from the die.

undercuts

When designing chamfers on PM parts, a minimum angle of __________ is preferred to prevent fragile sharp corners on punches.

$$45^\circ$$

To maintain structural integrity and tool strength in PM part design, the minimum recommended wall thickness is __________ (or $0.060\,\text{in}$).

$$1.5\,\text{mm}$$