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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. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Superconductivity
Two ways to measure heat capacity
Critical Properties of Superconductive Materials
Thermal Expansion: Asymmetric curve
2. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
HB (Brinell Hardness)
Two ways to measure heat capacity
Film Deposition
Lithography
3. Typical loading conditions are _____ enough to break all inter-atomic bonds
Luminescence examples
Impact energy
Not severe
HB (Brinell Hardness)
4. High toughness; material resists crack propagation.
Magnetic Storage
High impact energy
Film Deposition
Why materials fail in service
5. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Work Hardening
Energy States: Insulators and Semiconductors
Modulus of Rupture (MOR)
Stress Intensity Factor
6. A parallel-plate capacitor involves an insulator - or dielectric - between two metal electrodes. The charge density buildup at the capacitor surface is related to the dielectric constant of the material.
How an LCD works
Fatigue
HB (Brinell Hardness)
Insulators
7. Cracks pass through grains - often along specific crystal planes.
Internal magnetic moments
Transgranular Fracture
High impact energy
Iron-Silicon Alloy in Transformer Cores
8. - 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
Luminescence
Paramagnetic Materials
Lithography
Insulators
9. These materials are relatively unaffected by magnetic fields.
Diamagnetic Materials
Hard Magnetic Materials
Elastic Deformation
Energy States: Insulators and Semiconductors
10. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Translucent
Ductile Fracture
Metallization
What do magnetic moments arise from?
11. 1. Tc= critical temperature- if T>Tc not superconducting 2. Jc= critical current density - if J>Jc not superconducting 3. Hc= critical magnetic field - if H > Hc not superconducting
Incident Light
Brittle Fracture
Critical Properties of Superconductive Materials
Reflectance of Non-Metals
12. 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.
Response to a Magnetic Field
Charpy or Izod test
Liquid Crystal Displays (LCD's)
Plastic Deformation (Metals)
13. 1. Ability of the material to absorb energy prior to fracture 2. Short term dynamic stressing - Car collisions - Bullets - Athletic equipment 3. This is different than toughness; energy necessary to push a crack (flaw) through a material 4. Useful in
Impact - Toughness
The Transistor
Work Hardening
IC Devices: P-N Rectifying Junction
14. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Opacity
Hard Magnetic Materials
Soft Magnetic Materials
Relative Permeability
15. If a material has ________ - then the field generated by those moments must be added to the induced field.
Thermal Stresses
Domains in Ferromagnetic & Ferrimagnetic Materials
The Transistor
Internal magnetic moments
16. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
There is no perfect material?
Color
How to gage the extent of plastic deformation
Conduction & Electron Transport
17. Occur when lots of dislocations move.
Slip Bands
True Strain
Ductile Materials
Magnetic Storage
18. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Incoherent
High impact energy
How to gage the extent of plastic deformation
Transgranular Fracture
19. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Engineering Fracture Performance
Heat Capacity
Ductile Fracture
Domains in Ferromagnetic & Ferrimagnetic Materials
20. Another optical property - Depends on the wavelength of the visible spectrum.
4 Types of Magnetism
Diamagnetic Materials
Color
Not severe
21. 1. Tensile (opening) 2. Sliding 3. Tearing
Film Deposition
Slip Bands
Fatigue
The three modes of crack surface displacement
22. Becomes harder (more strain) to stretch (elongate)
Opacity
Conduction & Electron Transport
Work Hardening
Scattering
23. 1. Stress-strain behavior is not usually determined via tensile tests 2. Material fails before it yields 3. Bend/flexure tests are often used instead.
Sparkle of Diamonds
Meissner Effect
Refraction
Brittle Ceramics
24. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
How an LCD works
Engineering Fracture Performance
Magnetic Storage Media Types
Heat Capacity from an Atomic Prospective
25. Without passing a current a continually varying magnetic field will cause a current to flow
Brittle Ceramics
Insulators
There is no perfect material?
Response to a Magnetic Field
26. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Dependence of Heat Capacity on Temperature
Griffith Crack Model
Critical Properties of Superconductive Materials
Heat Capacity from an Atomic Prospective
27. Emitted light is in phase
Iron-Silicon Alloy in Transformer Cores
Impact energy
Stress Intensity Factor
Coherent
28. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
There is no perfect material?
What do magnetic moments arise from?
Two ways to measure heat capacity
True Stress
29. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
Meissner Effect
Hysteresis and Permanent Magnetization
Slip Bands
Metals: Resistivity vs. T - Impurities
30. - Metals that exhibit high ductility - exhibit high toughness. Ceramics are very strong - but have low ductility and low toughness - Polymers are very ductile but are not generally very strong in shear (compared to metals and ceramics). They have low
Response to a Magnetic Field
Etching
Scattering
Stress Intensity values
31. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Brittle Fracture
Fatigue
Conduction & Electron Transport
Not severe
32. These materials are "attracted" to magnetic fields.
Brittle Fracture
Specific Heat
Paramagnetic Materials
Meissner Effect
33. A high index of refraction (n value) allows for multiple internal reactions.
Sparkle of Diamonds
Metals: Resistivity vs. T - Impurities
Linewidth
Reflectance of Non-Metals
34. # of thermally generated electrons = # of holes (broken bonds)
Ductile Materials
Intrinsic Semiconductors
Magnetic Storage
Electromigration
35. A three terminal device that acts like a simple "on-off" switch. (the basis of Integrated Circuits (IC) technology - used in computers - cell phones - automotive control - etc) - If voltage (potential) applied to the "gate" - current flows between th
Dependence of Heat Capacity on Temperature
The Transistor
Magnetic Storage
Opacifiers
36. Materials change size when temperature is changed
Thermal expansion
What do magnetic moments arise from?
Internal magnetic moments
Color
37. 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
Scattering
Refraction
The three modes of crack surface displacement
Metallization
38. Width of smallest feature obtainable on Si surface
Intrinsic Semiconductors
Linewidth
Superconductivity
Domains in Ferromagnetic & Ferrimagnetic Materials
39. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
True Stress
Liquid Crystal Displays (LCD's)
To improve fatigue life
Stress Intensity Factor
40. A measure of the ease with which a B field can be induced inside a material.
Relative Permeability
Thermal Shock Resistance
Reflectance of Non-Metals
Electrical Conduction
41. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION
42. 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
Paramagnetic Materials
Hard Magnetic Materials
Specific Heat
How an LCD works
43. 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.
Magnetic Storage Media Types
Domains in Ferromagnetic & Ferrimagnetic Materials
To improve fatigue life
Reflectance of Non-Metals
44. Metals are good conductors since their _______is only partially filled.
Generation of a Magnetic Field - Within a Solid Material
Reflectance of Non-Metals
Valence band
Coefficient of Thermal Expansion
45. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Impact energy
Superconductivity
IC Devices: P-N Rectifying Junction
Holloman Equation
46. Growth of an oxide layer by the reaction of oxygen with the substrate - Provides dopant masking and device isolation - IC technology uses 1. Thermal grown oxidation (dry) 2. Wet Oxidation 3. Selective Oxidation
Color
Thermal Stresses
M is known as what?
Oxidation
47. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Two ways to measure heat capacity
Yield and Reliability
Soft Magnetic Materials
Pure Semiconductors: Conductivity vs. T
48. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Coefficient of Thermal Expansion
Force Decomposition
LASER
IC Devices: P-N Rectifying Junction
49. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Electrical Conduction
Force Decomposition
Fatigue
Valence band
50. Occurs at a single pore or other solid by refraction n = 1 for pore (air) n > 1 for the solid - n ~ 1.5 for glass - Scattering effect is maximized by pore/particle size within 400-700 nm range - Reason for Opacity in ceramics - glasses and polymers.
Scattering
Etching
Conduction & Electron Transport
Translucent