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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. 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.
Response to a Magnetic Field
Insulators
Thermal Shock Resistance
Relative Permeability
2. Another optical property - Depends on the wavelength of the visible spectrum.
Color
Thermal expansion
Holloman Equation
Lithography
3. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Iron-Silicon Alloy in Transformer Cores
Reflectance of Non-Metals
Soft Magnetic Materials
Metallization
4. 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
Iron-Silicon Alloy in Transformer Cores
The Transistor
IC Devices: P-N Rectifying Junction
Influence of Temperature on Magnetic Behavior
5. 1. Yield = ratio of functional chips to total # of chips - Most yield loss during wafer processing - b/c of complex 2. Reliability - No device has infinite lifetime. Statistical methods to predict expected lifetime - Failure mechanisms: Diffusion reg
Heat Capacity
Two kinds of Reflection
Response to a Magnetic Field
Yield and Reliability
6. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
IC Devices: P-N Rectifying Junction
Hysteresis and Permanent Magnetization
4 Types of Magnetism
Iron-Silicon Alloy in Transformer Cores
7. These materials are relatively unaffected by magnetic fields.
Diamagnetic Materials
Incident Light
Intergranular Fracture
Intrinsic Semiconductors
8. 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
Reflection of Light for Metals
Electromigration
Bending tests
Oxidation
9. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Coefficient of Thermal Expansion
Modulus of Rupture (MOR)
Etching
Valence band
10. 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.
Stress Intensity Factor
Reflectance of Non-Metals
Holloman Equation
Force Decomposition
11. A high index of refraction (n value) allows for multiple internal reactions.
Insulators
Sparkle of Diamonds
Heat Capacity
4 Types of Magnetism
12. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Superconductivity
M is known as what?
Transgranular Fracture
Why materials fail in service
13. A measure of the ease with which a B field can be induced inside a material.
Modulus of Rupture (MOR)
Thermal Stresses
Opaque
Relative Permeability
14. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Relative Permeability
LASER
To improve fatigue life
Film Deposition
15. 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.
Refraction
Thermal Expansion: Symmetric curve
Paramagnetic Materials
Opaque
16. Specific heat = energy input/(mass*temperature change)
Two kinds of Reflection
Thermal Stresses
Specific Heat
Luminescence
17. 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
Reflection of Light for Metals
Influence of Temperature on Magnetic Behavior
Why do ceramics have larger bonding energy?
HB (Brinell Hardness)
18. Because of ionic & covalent-type bonding.
Why do ceramics have larger bonding energy?
Transparent
True Stress
Film Deposition
19. The size of the material changes with a change in temperature - polymers have the largest values
Coefficient of Thermal Expansion
Heat Capacity from an Atomic Prospective
Opacifiers
Ductile Fracture
20. Resistance to plastic deformation of cracking in compression - and better wear properties.
Intrinsic Semiconductors
Heat Capacity from an Atomic Prospective
Large Hardness
Brittle Ceramics
21. Wet: isotropic - under cut Dry: ansiotropic - directional
Brittle Ceramics
Etching
Influence of Temperature on Magnetic Behavior
Valence band
22. 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
Lithography
Yield and Reliability
Meissner Effect
Magnetic Storage
23. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Coefficient of Thermal Expansion
Meissner Effect
Soft Magnetic Materials
Griffith Crack Model
24. # of thermally generated electrons = # of holes (broken bonds)
Pure Semiconductors: Conductivity vs. T
Intrinsic Semiconductors
Internal magnetic moments
Why fracture surfaces have faceted texture
25. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Heat Capacity from an Atomic Prospective
Elastic Deformation
Pure Semiconductors: Conductivity vs. T
Film Deposition
26. Cracks propagate along grain boundaries.
Meissner Effect
Ductile Fracture
Engineering Fracture Performance
Intergranular Fracture
27. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Lithography
Incoherent
Why fracture surfaces have faceted texture
Impact energy
28. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Scattering
Influence of Temperature on Magnetic Behavior
There is no perfect material?
Rockwell
29. 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.
Metallization
Brittle Ceramics
To improve fatigue life
Refraction
30. 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.
Response to a Magnetic Field
Scattering
True Stress
Impact energy
31. Measures Hardness - No major sample damage - Each scales runs to 130 but only useful in range 20-100 - Minor load is 10 kg - Major load: 60 kg (diamond) - 100 kg (1/16 in. ball) - 150 kg (diamond)
Rockwell
HB (Brinell Hardness)
Opaque
Iron-Silicon Alloy in Transformer Cores
32. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Dependence of Heat Capacity on Temperature
Film Deposition
Extrinsic Semiconductors
Fatigue
33. Created by current through a coil N= total number of turns L= length of turns (m) I= current (ampere) H= applied magnetic field (ampere-turns/m) Bo= magnetic flux density in a vacuum (tesla)
Opacifiers
Paramagnetic Materials
Conduction & Electron Transport
Generation of a Magnetic Field - Vacuum
34. Metals are good conductors since their _______is only partially filled.
Fatigue
Intrinsic Semiconductors
Impact - Toughness
Valence band
35. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Conduction & Electron Transport
Domains in Ferromagnetic & Ferrimagnetic Materials
Stages of Failure: Ductile Fracture
Sparkle of Diamonds
36. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Stages of Failure: Ductile Fracture
Magnetic Storage Media Types
Why materials fail in service
Intergranular Fracture
37. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
True Stress
Response to a Magnetic Field
Refraction
Meissner Effect
38. Cracks pass through grains - often along specific crystal planes.
Force Decomposition
Modulus of Rupture (MOR)
Transgranular Fracture
Metallization
39. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Metallization
Thermal Shock Resistance
Incoherent
Meissner Effect
40. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Generation of a Magnetic Field - Within a Solid Material
Ductile-to-Brittle Transition
Etching
Relative Permeability
41. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Domains in Ferromagnetic & Ferrimagnetic Materials
Yield and Reliability
Magnetic Storage
Translucent
42. There is always some statistical distribution of flaws or defects.
Yield and Reliability
Fourier's Law
There is no perfect material?
Meissner Effect
43. 1. Fluorescent Lamp - tungstate or silicate coating on inside of tube emits white light due to UV light generated inside the tube. 2. TV screen - emits light as electron beam is scanned back and forth.
Luminescence examples
Modulus of Rupture (MOR)
Charpy or Izod test
Transgranular Fracture
44. Stress concentration at a crack tips
Griffith Crack Model
Domains in Ferromagnetic & Ferrimagnetic Materials
Generation of a Magnetic Field - Within a Solid Material
Magnetic Storage
45. Typical loading conditions are _____ enough to break all inter-atomic bonds
Translucent
Response to a Magnetic Field
Paramagnetic Materials
Not severe
46. Defines the ability of a material to resist fracture even when a flaw exists - Directly depends on size of flaw and material properties - K(ic) is a materials constant
Stress Intensity Factor
M is known as what?
Reflection of Light for Metals
How an LCD works
47. For a metal - there is no ______ - only reflection
Refraction
Domains in Ferromagnetic & Ferrimagnetic Materials
Generation of a Magnetic Field - Vacuum
Griffith Crack Model
48. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Two ways to measure heat capacity
Not severe
Holloman Equation
Color
49. The ability of a material to be rapidly cooled and not fracture
Not severe
Hysteresis and Permanent Magnetization
Thermal Shock Resistance
The three modes of crack surface displacement
50. Materials change size when temperature is changed
Force Decomposition
Large Hardness
M is known as what?
Thermal expansion