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Test your basic knowledge |
Engineering Materials
Start Test
Study First
Subject
:
engineering
Instructions:
Answer 50 questions in 15 minutes.
If you are not ready to take this test, you can
study here
.
Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.
This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. There is always some statistical distribution of flaws or defects.
There is no perfect material?
Incident Light
Response to a Magnetic Field
Generation of a Magnetic Field - Within a Solid Material
2. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Thermal Expansion: Symmetric curve
Brittle Ceramics
Hard Magnetic Materials
Electromigration
3. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Work Hardening
Film Deposition
Thermal Expansion: Symmetric curve
Luminescence
4. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Extrinsic Semiconductors
Luminescence examples
Metallization
Impact - Toughness
5. The size of the material changes with a change in temperature - polymers have the largest values
Refraction
Coefficient of Thermal Expansion
Work Hardening
Two ways to measure heat capacity
6. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
LASER
Meissner Effect
Reflection of Light for Metals
To improve fatigue life
7. Typical loading conditions are _____ enough to break all inter-atomic bonds
Not severe
Diamagnetic Materials
Thermal Expansion: Symmetric curve
Dependence of Heat Capacity on Temperature
8. Diffuse image
Plastic Deformation (Metals)
4 Types of Magnetism
M is known as what?
Translucent
9. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Pure Semiconductors: Conductivity vs. T
Influence of Temperature on Magnetic Behavior
Not severe
Why do ceramics have larger bonding energy?
10. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Lithography
Dependence of Heat Capacity on Temperature
Engineering Fracture Performance
Intrinsic Semiconductors
11. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Luminescence
To improve fatigue life
Charpy or Izod test
Brittle Fracture
12. The magnetic hysteresis phenomenon: Stage 1: Initial (unmagnetized state) Stage 2: Apply H - align domains Stage 3: Remove H - alignment remains => Permanent magnet Stage 4: Coercivity - Hc negative H needed to demagnitize Stage 5: Apply -H - align d
Generation of a Magnetic Field - Vacuum
Brittle Fracture
Charpy or Izod test
Hysteresis and Permanent Magnetization
13. Degree of opacity depends on size and number of particles - Opacity of metals is the result of conduction electrons absorbing photons in the visible range.
Brittle Ceramics
Slip Bands
Intrinsic Semiconductors
Opacity
14. They are used to assess properties of ceramics & glasses.
Bending tests
Fatigue
Brittle Fracture
Oxidation
15. The ability of a material to absorb heat - Quantitatively: The energy required to produce a unit rise in temperature for one mole of a material.
Scattering
Generation of a Magnetic Field - Within a Solid Material
LASER
Heat Capacity
16. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
Influence of Temperature on Magnetic Behavior
Sparkle of Diamonds
Incoherent
Ductile-to-Brittle Transition
17. Transmitted light distorts electron clouds - The velocity of light in a material is lower than in a vacuum - Adding large ions to glass decreases the speed of light in the glass - Light can be "bent" (or refracted) as it passes through a transparent
Refraction
Incoherent
To improve fatigue life
Opaque
18. Another optical property - Depends on the wavelength of the visible spectrum.
Color
The Transistor
Hardness
Impact energy
19. Sigma=ln(li/lo)
True Strain
Transgranular Fracture
Opacity
Reflection of Light for Metals
20. Loss of image transmission - You get no image - There is no light transmission - and therefore reflects - scatters - or absorbs ALL of it. Both mirrors and carbon black are opaque.
Incident Light
Where does DBTT occur?
Opaque
Thermal Shock Resistance
21. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Coefficient of Thermal Expansion
Thermal Stresses
Heat Capacity from an Atomic Prospective
Metallization
22. Increase temperature - no increase in interatomic separation - no thermal expansion
Thermal Expansion: Symmetric curve
Response to a Magnetic Field
Ductile Fracture
Engineering Fracture Performance
23. Liquid polymer at room T - sandwiched between two sheets of glass - coated with transparent - electrically conductive film. - Character forming letters/ numbers etched on the face - Voltage applied disrupts the orientation of the rod- shaped molecule
Shear and Tensile Stress
The three modes of crack surface displacement
How an LCD works
Force Decomposition
24. These materials are "attracted" to magnetic fields.
Soft Magnetic Materials
Paramagnetic Materials
Refraction
Transgranular Fracture
25. # of thermally generated electrons = # of holes (broken bonds)
Stages of Failure: Ductile Fracture
Heat Capacity
Intrinsic Semiconductors
IC Devices: P-N Rectifying Junction
26. Not ALL the light is refracted - SOME is reflected. Materials with a high index of refraction also have high reflectance - High R is bad for lens applications - since this leads to undesirable light losses or interference.
Reflectance of Non-Metals
Etching
How to gage the extent of plastic deformation
Luminescence examples
27. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Critical Properties of Superconductive Materials
Magnetic Storage Media Types
Incident Light
Ductile Materials
28. Width of smallest feature obtainable on Si surface
Linewidth
Charpy or Izod test
Electrical Conduction
Two ways to measure heat capacity
29. Reflectiviy is between 0.90 and 0.95 - Metal surfaces appear shiny - Most of absorbed light is reflected at the same wavelength (NO REFRACTION) - Small fraction of light may be absorbed - Color of reflected light depends on wavelength distribution of
Electromigration
Transgranular Fracture
Reflection of Light for Metals
Elastic Deformation
30. Plastic means permanent! When a small load is applied - bonds stretch & planes shear. Then when the load is no longer applied - the planes are still sheared.
Plastic Deformation (Metals)
Dependence of Heat Capacity on Temperature
Refraction
Valence band
31. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
HB (Brinell Hardness)
Coherent
Iron-Silicon Alloy in Transformer Cores
Stress Intensity Factor
32. Because of ionic & covalent-type bonding.
Force Decomposition
Why do ceramics have larger bonding energy?
Influence of Temperature on Magnetic Behavior
Impact - Toughness
33. Occur when lots of dislocations move.
Slip Bands
Yield and Reliability
Liquid Crystal Displays (LCD's)
Extrinsic Semiconductors
34. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Slip Bands
IC Devices: P-N Rectifying Junction
Hardness
True Strain
35. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Superconductivity
Dependence of Heat Capacity on Temperature
Coefficient of Thermal Expansion
Translucent
36. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
4 Types of Magnetism
What do magnetic moments arise from?
Transgranular Fracture
Heat Capacity
37. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Translucent
Why do ceramics have larger bonding energy?
Superconductivity
Lithography
38. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Dependence of Heat Capacity on Temperature
Electromigration
Coherent
Impact - Toughness
39. A high index of refraction (n value) allows for multiple internal reactions.
Incident Light
Sparkle of Diamonds
Influence of Temperature on Magnetic Behavior
Hysteresis and Permanent Magnetization
40. Emitted light is in phase
Oxidation
Soft Magnetic Materials
Two kinds of Reflection
Coherent
41. Digitalized data in the form of electrical signals are transferred to and recorded digitally on a magnetic medium (tape or disk) - This transference is accomplished by a recording system that consists of a read/write head - "write" or record data by
Critical Properties of Superconductive Materials
Magnetic Storage
Elastic Deformation
LASER
42. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
There is no perfect material?
Heat Capacity from an Atomic Prospective
Why do ceramics have larger bonding energy?
Stages of Failure: Ductile Fracture
43. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Thermal Stresses
Film Deposition
Refraction
Stress Intensity Factor
44. Undergo extensive plastic deformation prior to failure.
Thermal Expansion: Symmetric curve
Ductile Materials
Transparent
Relative Permeability
45. Rho=F/A - tau=G/A . Depending on what angle the force is applied - and what angle the crystal is at - it takes different amounts of force to induce plastic deformation.
Ductile Fracture
High impact energy
LASER
Shear and Tensile Stress
46. Wet: isotropic - under cut Dry: ansiotropic - directional
Etching
Linewidth
Transgranular Fracture
Metals: Resistivity vs. T - Impurities
47. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Engineering Fracture Performance
Translucent
Charpy or Izod test
Metals: Resistivity vs. T - Impurities
48. Ability to transmit a clear image - The image is clear.
Iron-Silicon Alloy in Transformer Cores
Transparent
Stages of Failure: Ductile Fracture
Yield and Reliability
49. - The emission of light from a substance due to the absorption of energy. (Could be radiation - mechanical - or chemical energy. Could also be energetic particles.) - Traps and activator levels are produced by impurity additions to the material - Whe
Force Decomposition
Magnetic Storage
Luminescence
Where does DBTT occur?
50. Resistance to plastic deformation of cracking in compression - and better wear properties.
Large Hardness
Internal magnetic moments
Liquid Crystal Displays (LCD's)
Linewidth