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1.1 Define manufacturing.

Manufacturing is the application of physical and chemical processes to alter a material’s geometry, properties, and/or appearance to make parts or products; it also includes assembly. Economically, it is the transformation of materials into items of greater value.

1.2 What is the difference between consumer goods and capital goods? Give some examples in each category.

Consumer goods are products purchased directly by consumers, such as cars, TVs, computers, and toys. Capital goods are products used by other companies to produce goods or provide services, such as machine tools, factory equipment, tractors, and airplanes.

1.3 What is the difference between soft product variety and hard product variety?

Soft product variety means different product models are produced from the same basic product design with small differences. Hard product variety means the products differ substantially in design, function, size, or style.

1.4 How are product variety and production quantity related when comparing typical factories?

Product variety and production quantity are generally inversely related: high product variety usually means low production quantity, while low variety usually means high quantity.

1.5 One of the dimensions of manufacturing capability is technological processing capability. Define technological processing capability.

Technological processing capability is the set of available manufacturing processes a plant can perform and the limits of those processes in terms of work material, part geometry, size, weight, and tolerances.

1.6 What are the four categories of engineering materials used in manufacturing?

Metals, ceramics, polymers, and composite materials.

1.7 What is the definition of steel?

Steel is an iron-carbon alloy containing about 0.02% to 2.11% carbon.

1.8 What are some of the typical applications of steel?

Steel is commonly used in construction, automobiles, machinery, tools, appliances, pipelines, and structural components.

1.9 What is the difference between a thermoplastic polymer and a thermosetting polymer?

Thermoplastics can be reheated and reshaped multiple times without major molecular change. Thermosets cure into a rigid structure and cannot be remelted and reshaped.

1.10 What is the defining characteristic or property of an elastomer?

An elastomer can be stretched to a large strain and then return to its original shape.

1.11 Manufacturing processes are usually accomplished as unit operations. Define unit operation.

A unit operation is a single step in a sequence of steps used to transform a material or assemble a product.

1.12 In manufacturing processes, what is the difference between a processing operation and an assembly operation?

A processing operation changes a work material’s shape, properties, or appearance. An assembly operation joins two or more components to create a new entity.

1.13 What is the difference between casting and molding?

Casting usually refers to shaping metals by pouring molten material into a mold, while molding usually refers to shaping polymers and some other materials in a cavity.

1.14 Particulate processing is generally associated with the processing of which two of the three types of engineering materials?

Ceramics and metals.

1.15 What is the most common reason for heating a metallic workpiece before it is subjected to a deformation process?

To reduce strength and increase ductility so the metal is easier to deform.

1.16 What is a machining operation?

A machining operation is a material-removal process in which a sharp cutting tool removes excess material from a workpart.

1.17 Name the three most important machining operations.

Turning, drilling, and milling.

1.18 What is the most important property-enhancing operation?

Heat treatment.

1.19 Identify the four types of permanent joining processes used in assembly.

Welding, brazing, soldering, and adhesive bonding.

1.20 What is a machine tool?

A machine tool is a power-driven machine used to operate cutting tools and perform machining with high precision and control.

1.21 Define batch production and describe why it is often used for medium-quantity production.

Batch production is when groups or lots of parts are processed together through operations. It is used for medium quantities because changeover time can be spread across many parts, reducing average time per part.

1.22 With which production quantity range is cellular manufacturing most closely associated?

Medium production.

1.23 Name two departments that are typically classified as manufacturing support departments.

Examples include manufacturing engineering and production control.

21.1 What are the geometric differences between rotational parts and nonrotational parts in machining, and what machine tools are used for each type?

Rotational parts are cylindrical or disk-shaped and are machined on turning machines such as lathes. Nonrotational parts are block-shaped or flat and are generally machined on milling machines, shapers, or planers.

21.2 Does the term prismatic refer to rotational or nonrotational parts?

Nonrotational parts.

21.3 Distinguish between generating and forming when machining part geometries.

In generating, the shape is created by the relative path of the tool and workpart. In forming, the shape is created by the form of the cutting edge itself.

21.4 In which category is plain milling classified, generating or forming?

Generating.

21.5 In which category is taper turning classified, generating or forming?

Generating.

21.6 In which category is a broaching operation classified, generating or forming?

Forming.

21.7 In which category is a boring operation classified, generating or forming?

Generating.

21.8 In which category is profile milling classified, generating or forming?

Forming.

21.9 Describe the turning process.

Turning is a machining process in which a single-point cutting tool removes material from the outside of a rotating cylindrical workpiece.

21.10 In a straight turning operation, the final diameter of the workpiece is equal to the starting diameter minus the depth of cut, true or false?

False. The final diameter equals the starting diameter minus twice the depth of cut.

21.11 How does a boring operation differ from a turning operation?

Boring creates or enlarges an internal cylindrical surface from an existing hole, while turning creates an external cylindrical surface.

21.12 Among the components of an engine lathe, what are the headstock and tailstock?

The headstock contains the spindle and drive mechanism to rotate the work. The tailstock supports the opposite end of the work or holds tools such as drills.

21.13 What is meant by the lathe designation 30 cm × 90 cm (12 in × 36 in)?

It means the lathe has a 30 cm swing and 90 cm distance between centers.

21.14 Name four methods by which a work part can be held in a lathe.

Between centers, in a chuck, in a collet, and on a faceplate.

21.15 What is the difference between a live center and a dead center, when these terms are used in the context of workholding in a lathe?

A live center rotates with the work, while a dead center does not rotate.

21.16 Why is a six-spindle bar machine more productive than a single-spindle bar machine?

Because it performs multiple operations simultaneously on different spindles, increasing output.

21.17 Which type of boring machine, vertical or horizontal, would be most appropriate for a large workpiece having a diameter that is greater than its length?

Vertical boring machine.

21.18 What geometric shape is created by a drilling operation that uses a conventional twist drill?

A round hole with a conical bottom.

21.19 How is feed defined in a drilling operation that uses a conventional twist drill?

Feed is the distance the drill penetrates into the work during each revolution.

21.20 What is the purpose of a tapping operation?

To cut internal threads in a hole.

21.21 What is the difference between counterboring and countersinking?

Counterboring creates a flat-bottom cylindrical enlargement at the top of a hole. Countersinking creates a conical enlargement at the top of a hole.

21.22 What is the distinguishing feature of a radial drill press?

The drill head can move along a radial arm and the arm can swing, allowing holes to be drilled at different positions without moving the workpiece.

21.23 What is the difference between a fixture and a jig?

Both are work-holding devices. A fixture holds the workpiece in place; a jig holds the workpiece and also guides the tool.

21.24 What is a milling operation in the context of machining?

Milling is a machining process in which a rotating multi-tooth cutter removes material from a workpiece.

21.25 What is a fly-cutter as used in a milling operation?

A fly-cutter is a single-point cutting tool mounted on a rotating spindle for milling.

21.26 What is the difference between peripheral milling and face milling?

In peripheral milling, the cutter axis is parallel to the surface being machined and cutting is done by the cutter’s outside edge. In face milling, the cutter axis is perpendicular to the surface and cutting is done by the face and periphery.

21.27 Describe profile milling.

Profile milling is milling performed along the outside or inside contour of a flat part.

21.28 What is the chip load in a milling operation?

Chip load is the amount of material removed by each tooth per revolution, usually expressed as feed per tooth.

21.29 How does a universal milling machine differ from a conventional knee-and-column machine?

A universal milling machine has a table that can swivel to various angles, allowing more versatile operations.

21.30 What is a machining center?

A machining center is a highly automated machine tool capable of performing multiple operations such as milling and drilling, usually with automatic tool changing and pallet handling.

21.31 How does an automatic pallet storage and handling system enable unattended operation of a machining center?

It automatically loads and unloads workparts or pallets, allowing the machine to continue running without an operator.

21.32 What is the difference between a machining center and a turning center?

A machining center is designed mainly for rotating cutting tools such as in milling and drilling, while a turning center is designed mainly for rotating workpieces as in turning.

21.33 Shaping and planing operations involve interrupted cutting, true or false?

True.

21.34 How do shaping and planing differ?

In shaping, the tool moves and the work is stationary during the cut. In planing, the work moves and the tool is stationary during the cut.

21.35 Broaching is performed using a rotating multi-tooth cutting tool, true or false?

False.

21.36 What is the difference between internal broaching and external broaching?

Internal broaching cuts surfaces inside a hole, while external broaching cuts surfaces on the outside of a workpart.

21.37 Thread milling is used for cutting threads that are too large to be accomplished by thread chasing, true or false?

True.

21.38 What is the name of the most common process for cutting internal threads?

Tapping.

2.1 The elements listed in the Periodic Table can be divided into three categories. What are these categories and give an example of each?

The three categories of elements are metals (e.g., aluminum), nonmetals (e.g., oxygen), and semimetals (e.g., silicon).

2.2 Which elements are the noble metals?

The noble metals are ruthenium, rhodium, palladium, silver, osmium, iridium, platinum, and gold.

2.3 What is the difference between primary and secondary bonding in the structure of materials?

Primary bonding is strong bonding between atoms in a material, such as ionic, covalent, and metallic bonding. Secondary bonding is weaker attraction between molecules or parts of molecules, such as van der Waals and hydrogen bonding.

2.4 What is the difference between crystalline and noncrystalline structures in materials?

A crystalline structure has atoms arranged in a regular, repeating pattern called a lattice. A noncrystalline structure has no long-range repeating atomic order.

2.5 Among the common point defects in a crystal lattice structure, what is a vacancy?

A vacancy is a missing atom in the lattice structure.

2.6 Among the common point defects in a crystal lattice structure, what is an ion-pair vacancy?

An ion-pair vacancy is a pair of missing ions of opposite charge in an ionic crystal, maintaining overall charge neutrality.

2.7 Among the common point defects in a crystal lattice structure, what is an interstitialcy?

An interstitialcy is a point defect in which an atom occupies a normally empty space between atoms in the lattice.

2.8 Define the difference between elastic and plastic deformation in terms of the effect on the crystal lattice structure.

Elastic deformation is a temporary shift in atomic spacing that disappears when the load is removed. Plastic deformation is a permanent rearrangement or slipping of atoms in the lattice after the load is removed.

2.9 Identify some materials that have a crystalline structure.

Most metals, many ceramics, and some polymers have crystalline structure.

2.10 Identify some materials that possess a noncrystalline structure.

Examples include glass, many plastics, and rubber.

3.1 What are the three types of static stresses to which materials are subjected?

Tensile, compressive, and shear.

3.2 State Hooke’s law.

Hooke’s law states that stress is proportional to strain: σ = Eε.

3.3 Define tensile strength of a material.

Tensile strength is the maximum load experienced during a tensile test divided by the original cross-sectional area.

3.4 Define yield strength of a material.

Yield strength is the stress at which a material begins to plastically deform.

3.5 Why cannot a direct conversion be made between the ductility measures of elongation and reduction in area using the assumption of constant volume?

Because elongation is distributed over the entire gage length, while reduction in area is localized in the necked region, so the deformation is not uniform.

3.6 What is work hardening?

Work hardening is the increase in strength and hardness that occurs when a metal is plastically deformed.

3.7 Which stress always has the greater value, engineering stress or true stress?

True stress is always greater than engineering stress once deformation causes the cross-sectional area to decrease.

3.8 A stress–strain relationship that exhibits behavior that is elastic and perfectly plastic is characteristic of what types of materials?

It is characteristic of idealized materials and some annealed metals approximated as having no strain hardening.

3.9 A stress–strain relationship that exhibits behavior that is elastic and strain hardening is characteristic of what types of materials?

It is characteristic of most ductile metals at room temperature.

3.10 Under what circumstances does the strength coefficient have the same value as the yield strength?

When the material is perfectly plastic and does not strain harden.

3.11 What is the complicating factor that occurs in a compression test that might be considered analogous to necking in a tensile test?

Barreling of the specimen due to friction at the platen surfaces.

3.12 Tensile testing is not appropriate for hard brittle materials such as ceramics. What is the test commonly used to determine the strength properties of such materials?

A bending test, especially the transverse or flexure test.

3.13 By what failure mode do brittle materials such as ceramics fail in a bending test?

They fail by fracture, usually from crack initiation on the tensile side.

3.14 How is the shear modulus of elasticity G related to the tensile modulus of elasticity E, on average?

On average, G is about 0.4E.

3.15 How is shear strength S related to tensile strength TS, on average?

S = 0.7 TS, on average.

4.1 Define density as a material property.

Density is the mass per unit volume of a material.

4.2 Theoretically, the melting point and freezing point of a crystalline element, such as a metal, are the same temperature value, true or false?

True.

4.3 When a solid metallic element is heated to its melting temperature, it requires a certain amount of heat energy to transform to the liquid phase. What is the name of that heat energy?

The heat of fusion.

4.4 When a molten metal cools to its freezing point but remains in the liquid state below the freezing point, what is the term that describes this phenomenon?

Supercooling.

4.5 For a metal alloy, which temperature is higher than the other, liquidus or solidus?

Liquidus is higher than solidus.

4.6 Describe the melting characteristics of a noncrystalline material such as glass.

A noncrystalline material does not melt at one fixed temperature. It gradually softens over a range of temperatures and becomes increasingly fluid as temperature rises.

4.7 Define volumetric specific heat as a material property.

Volumetric specific heat is the amount of heat energy required to raise the temperature of a unit volume of material by one degree.

4.8 What is thermal conductivity as a material property?

Thermal conductivity is a material’s ability to conduct heat.

4.10 In machining operations, coolant fluids are often used to reduce cutting temperatures. What liquid material is almost always used as the base for these coolants because of its high heat-carrying capacity?

Water.

4.14 Define electrical conductivity as a material property.

Electrical conductivity is a material’s capacity to conduct electric current; it is the reciprocal of resistivity.

4.15 Why are metals better conductors of electricity than ceramics and polymers?

Because metals have free electrons that can move easily through the atomic structure, while ceramics and polymers do not.

4.16 What is a dielectric?

A dielectric is an insulating material that resists the flow of electric current and can support an electrostatic field.