Materials final list

What are the three basic classes of engineering materials?

Metals, ceramics and polymers.

What distinguishes primary from secondary industry?

Primary extracts raw materials; secondary transforms them into products.

What is a capital good?

Equipment used to produce other goods, such as a CNC machine.

How are product variety and production quantity usually related?

Higher product variety generally corresponds to lower production quantity.

What is batch production?

Making a specified quantity of identical products before changing production.

What distinguishes process and product layouts?

Process: similar machines grouped; product: machines arranged by operation sequence.

What is a manufacturing shaping process?

An operation that creates or changes the geometry of a workpart.

What are ferrous metals?

Metals whose principal constituent is iron.

What is an alloy?

A material combining elements, at least one being metallic.

What does wt% represent?

The mass percentage of a constituent in a material.

What does the α + β region of a phase diagram indicate?

Two distinct solid phases coexist at equilibrium.

What does a tie line identify in a two-phase region?

The compositions of the two coexisting phases at a given temperature.

What does the lever rule calculate?

The mass fractions of phases in a two-phase region.

What is a eutectic reaction?

One liquid transforms into two solid phases upon cooling.

What is a eutectoid reaction?

One solid phase transforms into two different solid phases.

What is pearlite?

A lamellar mixture of ferrite and cementite.

What is cementite's chemical formula?

Fe₃C.

What is the approximate eutectoid carbon composition of steel?

0.76 wt% carbon.

What is the main purpose of a welding process?

To permanently join materials through coalescence, often using heat.

What is welding power density?

Power supplied per unit area of the heated surface.

What does the welding heat-transfer factor represent?

The fraction of source energy delivered to the workpiece.

What does the welding melting factor represent?

The fraction of delivered heat used for melting.

What is the purpose of filler metal?

To provide additional material for forming a welded joint.

What distinguishes fusion welding from solid-state welding?

Fusion welding melts the joint; solid-state welding does not require melting.

What is mechanical fastening?

Joining parts with hardware such as bolts, screws or rivets.

What is turning?

Machining a rotating workpiece with a cutting tool.

What is drilling?

Producing a round hole using a rotating drill.

What is milling?

Removing material with a rotating multi-edge cutting tool.

What is cutting speed in machining?

The relative surface velocity between cutting edge and workpiece.

What are the usual units of spindle speed?

Revolutions per minute (rpm).

What is feed per revolution?

Distance advanced by the tool in one spindle revolution.

What does material removal rate measure?

Volume of material removed per unit time.

What happens to turning diameter when depth of cut increases?

The diameter reduction equals twice the radial depth of cut.

What is orthogonal cutting?

Cutting with the edge perpendicular to the cutting velocity.

What is chip thickness ratio?

Uncut chip thickness divided by deformed chip thickness.

Why is the formed chip usually thicker than the uncut layer?

Plastic deformation compresses and thickens the chip.

What is the shear plane angle?

The angle of the primary shear plane relative to cutting direction.

What does the coefficient of friction represent in machining?

The ratio of friction force to normal force at the tool–chip interface.

What is specific cutting energy?

Energy required to remove a unit volume of work material.

What does increasing cutting speed generally do to cutting temperature?

It generally increases the cutting temperature.

What is the purpose of cutting fluid?

Cooling, lubrication and sometimes chip removal.

What does Taylor's tool-life equation relate?

Cutting speed and cutting tool life: vTⁿ = C.

What usually happens to tool life as cutting speed increases?

Tool life decreases.

Which tool property is especially important for resisting impact?

Toughness.

What is hot hardness?

Ability to maintain hardness at elevated temperatures.

What is flank wear?

Wear on the cutting tool's clearance face.

What is crater wear?

Wear on the rake face caused by chip contact.

What does the tool nose radius influence in turning?

Surface roughness and the finish achievable at a given feed.

What is the distinction between maximum production and minimum cost speed?

One minimizes production time; the other minimizes cost per part.

What is casting?

Pouring liquid material into a mould and allowing it to solidify.

What is the function of a riser in casting?

Supplying molten metal to compensate for solidification shrinkage.

What is a sprue?

The passage carrying molten metal down into the mould gating system.

What is the purpose of a gating system?

To deliver and control molten metal flow into the mould cavity.

What does Chvorinov's rule predict?

Casting solidification time from its volume-to-surface-area ratio.

What happens to solidification time as V/A increases?

Solidification time increases.

What is bulk deformation?

Plastic shaping with substantial changes in workpiece dimensions.

How does hot working differ from cold working?

Hot working occurs above recrystallization temperature; cold working below it.

What is rolling?

Reducing thickness by compressing material between rotating rolls.

What is draft in rolling?

Initial thickness minus final thickness.

What effect does friction have on maximum rolling draft?

Greater friction permits a larger maximum draft.

What is forging?

Shaping metal through compressive forces applied by dies or tools.

What is strain hardening?

Increasing strength and hardness caused by plastic deformation.

What is blanking in sheet metalworking?

Cutting a sheet so the removed piece is the desired product.

What is punching in sheet metalworking?

Producing a hole; the removed slug is usually scrap.

What is springback in sheet-metal bending?

Partial elastic recovery after the bending force is removed.

What does drawing ratio compare?

Starting blank diameter divided by punch diameter.

What is the function of a blankholder?

To restrain sheet metal and reduce wrinkling during drawing.

What does process capability measure?

The natural variation of a manufacturing process.

What is the process capability index for a centered process?

Tolerance width divided by six standard deviations: PCI = T/(6σ).

What distinguishes X-bar charts from R charts?

X-bar monitors process means; R monitors variation within samples.