ME 381 Manufacturing HW5-7

Microsystem technology includes which of the following (three best answers): (a) LIGA technology, (b) microelectromechanical systems, (c) micromachines, (d) nanotechnology, (e) and precision engineering?

(a), (b), and (c).

Which one of the following is closest to the temperatures used in plasma arc cutting?

11,000°C (20,000°F)

Which one of the following materials is closest to diamond in hardness: aluminum oxide carbon dioxide cubic boron nitride silicon dioxide tungsten carbide

cubic boron nitride

Which one of the following is the most common element in the earth's crust: calcium iron oxygen aluminum silicon

oxygen

Etch factor is which of the following in chemical machining (more than one)? A = degree of anisotropy, C = specific removal rate, d = depth of cut, I = current, t = time, and u = undercut.

A d/u

Which of the following metals are used as the matrix material in fiber-reinforced MMCs (two best answers): Aluminum Iron Copper Zinc Magnesium

Aluminum Magnesium

Which of the following materials are used as fibers in fiber-reinforced plastics (four best answers): Cast Iron Aluminum oxide Epoxy Polyester Silicon Kevlar 49 E-glass Boron

Aluminum oxide Kevlar 49 E-glass Boron

Which of the following terms describes what a cemented carbide is (one best answer): Ceramic Cermet Composite Metal New ceramic Traditional ceramic

Cermet

Which of the following metals are used as the matrix metals in nearly all WC cemented carbides and TiC cermets (two correct answers): Lead Tungsten Cobalt Chromium Tungsten carbide Aluminum Nickel

Cobalt and Nickel

Which of the following processes would be appropriate to drill a hole with a square cross-section, 0.25 inch on a side and 1-inch deep in a steel workpiece (one best answer)?

EDM

Applications of electron beam machining are limited to metallic work materials due to the need for the work to be electrically conductive: T or F

F

Glass ceramics are polycrystalline ceramic structures that have been transformed into the glassy state: T or F

F

True or False: The reinforcing phase is the matrix within which the secondary phase is imbedded

F

Which one of the following reinforcing geometries offers the greatest potential for strength and stiffness improvement in the resulting composite material? Particles Fibres Flakes Infiltrated phase

Fibres

For a given weight of metallic powders, which of the following factors effect an increase in surface area? (two best answers): Higher shape factor Smaller particle size Large particle size Smaller shape factor

Higher shape factor Smaller particle size

Which of the following processes would be appropriate for cutting a hole of 0.003 inch diameter through a plate of aluminum that is 1/16-inch thick (one best answer)?

Laser beam machining

Wood is which one of the following composite types? CMC MMC PMC

PMC

Of the following processes, which one is noted for the highest material removal rates?

Plasma arc cutting

Identify which of the following materials are not composites (two correct answers): Wood Plywood Phenolic molding compound Cemented carbide Rubber in automobile tires Portland cement 1020 steel

Portland cement 1020 steel

Properties and characteristics of the glass-ceramics include which of the following (two best answers): Strong, relative to other ceramics High thermal expansion Efficiency in processing Electrical conductor

Strong, relative to other ceramics Efficiency in processing

Self-assembly is likely to be the most important of the nanofabrication processes because of its low cost, its capacity for producing structures over a range of sizes (from nanoscale to macroscale), and its general applicability to a wide variety of products. T or F

T

T or F: Ultrasonic machining can be used to machine both metallic and nonmetallic materials

T

Dip-pen nanolithography uses which one of the following techniques and/or devices: (a) atomic force microscope, (b) chemical vapor deposition, (c) electron beam lithography, (d) nano-imprint lithography, or (e) self-assembly?

a

Which of the following forms of radiation have wavelengths shorter than the wavelength of ultraviolet light used in photolithography (two correct answers): (a) electron beam radiation, (b) natural light, and (c) X-ray radiation?

a and c

Which of the following processes use mechanical energy as the principal energy source (may be more than one)? Grinding Milling Ultrasonic machining Water jet cutting

all of them

The aspect ratio in microsystem technology is best defined by which one of the following: (a) degree of anisotropy in etched features, (b) height-to-width ratio of the fabricated features, (c) height-to-width ratio of the MST device, (d) length-to-width ratio of the fabricated features, or (e) thickness-to-length ratio of the MST device?

b

Which of the following are considered techniques that fall within the category called top-down approaches to nanofabrication (three best answers): (a) biological evolution, (b) electron-beam lithography, (c) micro-imprint lithography, (d) scanning probe techniques, (e) self-assembly, and (f) X-ray lithography?

b, c, f

A self-assembled monolayer has a thickness that is which one of the following: (a) one micrometer, (b) one millimeter, (c) one molecule, or (d) one nanometer?

c

Which of the following are considered techniques that fall within the category called bottom-up approaches to nanofabrication (three best answers): (a) electron beam lithography, (b) extreme ultraviolet lithography, (c) chemical vapor deposition to produce carbon nanotubes, (d) nanoimprint lithography, (e) scanning probe techniques, (f) self-assembly, and (g) X-ray lithography?

c, e, f

Which of the following contains significant amounts of aluminum oxide (three correct answers): Kaolinite Silica Sandstone Quartz Feldspar Corundum Alumina Bauxite

corundum, alumina, bauxite

In the LIGA process, the letters LIGA stand for which one of the following: (a) let it go already, (b) little grinding apparatus, (c) lithographic applications, (d) lithography, electrodeposition, and plastic molding, or (e) lithography, grinding, and alteration?

d

The polymer used to make compact discs (CDs) and digital versatile discs (DVDs) is which one of the following: (a) amino resin, (b) epoxy resin, (c) polyamides, (d) polycarbonate, (e) polyethylene, or (f) polypropylene?

d

The most common work material used in microsystem technology is which one of the following: (a) boron, (b) gold, (c) nickel, (d) potassium hydroxide, or (e) silicon?

e

The three steps in correct order for sintering cycle in powder processing are [A], [B] and [C]

heat, sinter, and cool

Which of the following processes would be appropriate for cutting a narrow slot, less than 0.015 inch wide, in a 3/8- inch thick sheet of fiber-reinforced plastic (more than one)?

laser beam machining water jet cutting

Anisotropic means which one of the following: strength and other properties are a function of curing temperature composite materials with composition consisting of more than two materials properties vary depending on the direction in which they are measured properties are the same in every direction

properties vary depending on the direction in which they are measured

Chemical milling is used in which of the following (may be more than one)?

removing material to make shallow pockets in metal removing metal from aircraft wing panels

Glass products are based primarily on which one of the following minerals: Alumina Corundum Feldspar Kaolinite Silica

silica

Which of the following polymer types are most commonly used in polymer matrix composites: Elastomer Thermoplastics Thermosets

thermosets

Ceramic matrix composites are designed to overcome which of the following weaknesses of ceramics (two best answers): Hardness Hot hardness Toughness Modulus of elasticity Compressive Strength Tensile strength

toughness and tensile strength

Which one of the following terms refers to the glassy state of a material? Devitrified Vitreous Vitiated Crystalline Polycrystalline

vitreous