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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. 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.
Domains in Ferromagnetic & Ferrimagnetic Materials
Thermal Shock Resistance
Large Hardness
Opacity
2. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Relative Permeability
IC Devices: P-N Rectifying Junction
Metals: Resistivity vs. T - Impurities
Thermal Stresses
3. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Charpy or Izod test
Color
The Transistor
Heat Capacity from an Atomic Prospective
4. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
What do magnetic moments arise from?
Ductile-to-Brittle Transition
Brittle Fracture
Translucent
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
Fatigue
Specific Heat
Yield and Reliability
Thermal Shock Resistance
6. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Incoherent
Charpy or Izod test
Dependence of Heat Capacity on Temperature
Conduction & Electron Transport
7. If a material has ________ - then the field generated by those moments must be added to the induced field.
Sparkle of Diamonds
Intrinsic Semiconductors
Internal magnetic moments
Modulus of Rupture (MOR)
8. The Magnetization of the material - and is essentially the dipole moment per unit volume. It is proportional to the applied field. Xm is the magnetic susceptibility.
LASER
Reflectance of Non-Metals
M is known as what?
Ductile-to-Brittle Transition
9. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Brittle Fracture
Ductile Materials
Extrinsic Semiconductors
Metals: Resistivity vs. T - Impurities
10. 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.
Opaque
Sparkle of Diamonds
Metallization
Thermal Shock Resistance
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
Refraction
Critical Properties of Superconductive Materials
Impact - Toughness
Paramagnetic Materials
12. 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
Stress Intensity Factor
Why materials fail in service
The three modes of crack surface displacement
The Transistor
13. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Generation of a Magnetic Field - Vacuum
Elastic Deformation
Domains in Ferromagnetic & Ferrimagnetic Materials
Where does DBTT occur?
14. 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
How an LCD works
Insulators
Luminescence
Heat Capacity
15. Without passing a current a continually varying magnetic field will cause a current to flow
Response to a Magnetic Field
Intrinsic Semiconductors
Where does DBTT occur?
Luminescence
16. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
IC Devices: P-N Rectifying Junction
Pure Semiconductors: Conductivity vs. T
To improve fatigue life
Bending tests
17. 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
What do magnetic moments arise from?
Thermal Shock Resistance
Influence of Temperature on Magnetic Behavior
18. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Intergranular Fracture
What do magnetic moments arise from?
Thermal expansion
Translucent
19. 1. Tensile (opening) 2. Sliding 3. Tearing
The three modes of crack surface displacement
Pure Semiconductors: Conductivity vs. T
4 Types of Magnetism
Reflection of Light for Metals
20. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Work Hardening
Metallization
True Stress
Scattering
21. Sigma=ln(li/lo)
Metallization
True Strain
Dependence of Heat Capacity on Temperature
There is no perfect material?
22. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Fatigue
Incident Light
Stress Intensity Factor
Not severe
23. Width of smallest feature obtainable on Si surface
Linewidth
The Transistor
Shear and Tensile Stress
Lithography
24. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Meissner Effect
Reflectance of Non-Metals
Hardness
Soft Magnetic Materials
25. Different orientation of cleavage planes in grains.
Why do ceramics have larger bonding energy?
Why fracture surfaces have faceted texture
Luminescence examples
Yield and Reliability
26. Diffuse image
Translucent
The Transistor
How an LCD works
Stages of Failure: Ductile Fracture
27. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Metallization
Refraction
Rockwell
Stress Intensity Factor
28. 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.
Heat Capacity
Work Hardening
Superconductivity
Generation of a Magnetic Field - Within a Solid Material
29. Cracks pass through grains - often along specific crystal planes.
The Transistor
Transgranular Fracture
Intrinsic Semiconductors
Etching
30. Cracks propagate along grain boundaries.
Oxidation
Conduction & Electron Transport
Two kinds of Reflection
Intergranular Fracture
31. Increase temperature - no increase in interatomic separation - no thermal expansion
The three modes of crack surface displacement
Bending tests
Thermal Expansion: Symmetric curve
Critical Properties of Superconductive Materials
32. Measures impact energy 1. Strike a notched sample with an anvil 2. Measure how far the anvil travels following impact 3. Distance traveled is related to energy required to break the sample 4. Very high rate of loading. Makes materials more "brittle."
To improve fatigue life
Charpy or Izod test
The Transistor
Why fracture surfaces have faceted texture
33. For a metal - there is no ______ - only reflection
Scattering
Refraction
Insulators
Meissner Effect
34. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
35. Ability to transmit a clear image - The image is clear.
Transparent
Color
Reflection of Light for Metals
Electromigration
36. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Soft Magnetic Materials
Stress Intensity Factor
Conduction & Electron Transport
Thermal Shock Resistance
37. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Reflection of Light for Metals
Film Deposition
Stages of Failure: Ductile Fracture
What do magnetic moments arise from?
38. 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
True Strain
Why fracture surfaces have faceted texture
Reflection of Light for Metals
Oxidation
39. Specific heat = energy input/(mass*temperature change)
Opaque
Specific Heat
Stages of Failure: Ductile Fracture
Sparkle of Diamonds
40. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Brittle Materials
Influence of Temperature on Magnetic Behavior
Yield and Reliability
Metals: Resistivity vs. T - Impurities
41. 1. Ductility- % elongation - % reduction in area - may be of use in metal forming operations (e.g. - stretch forming). This is convenient for mechanical testing - but not very meaningful for most deformation processing. 2. Toughness- Area beneath str
Coherent
Superconductivity
Transgranular Fracture
How to gage the extent of plastic deformation
42. - 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
Why fracture surfaces have faceted texture
Color
Luminescence
Refraction
43. These materials are "attracted" to magnetic fields.
Reflection of Light for Metals
Engineering Fracture Performance
How to gage the extent of plastic deformation
Paramagnetic Materials
44. Metals are good conductors since their _______is only partially filled.
Shear and Tensile Stress
Luminescence examples
Brittle Ceramics
Valence band
45. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Ductile-to-Brittle Transition
High impact energy
Lithography
Why materials fail in service
46. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Translucent
Brittle Ceramics
Holloman Equation
Incoherent
47. Second phase particles with n > glass.
Thermal Conductivity
Opacifiers
Work Hardening
4 Types of Magnetism
48. High toughness; material resists crack propagation.
Luminescence examples
High impact energy
Elastic Deformation
Paramagnetic Materials
49. # of thermally generated electrons = # of holes (broken bonds)
The three modes of crack surface displacement
Engineering Fracture Performance
Intrinsic Semiconductors
Opaque
50. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Two kinds of Reflection
Domains in Ferromagnetic & Ferrimagnetic Materials
Scattering
IC Devices: P-N Rectifying Junction