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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. 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.
M is known as what?
Intrinsic Semiconductors
Holloman Equation
Incident Light
2. Process by which metal atoms diffuse because of a potential.
Work Hardening
Electromigration
Pure Semiconductors: Conductivity vs. T
Generation of a Magnetic Field - Within a Solid Material
3. 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
The Transistor
Influence of Temperature on Magnetic Behavior
True Stress
Two ways to measure heat capacity
4. Elastic means reversible! This is not a permanent deformation.
HB (Brinell Hardness)
Elastic Deformation
Internal magnetic moments
Translucent
5. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Coherent
Where does DBTT occur?
Brittle Fracture
Metals: Resistivity vs. T - Impurities
6. 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
Luminescence examples
True Stress
Influence of Temperature on Magnetic Behavior
7. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Incoherent
There is no perfect material?
HB (Brinell Hardness)
Insulators
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
Superconductivity
Etching
Two kinds of Reflection
9. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Dependence of Heat Capacity on Temperature
Domains in Ferromagnetic & Ferrimagnetic Materials
High impact energy
Coefficient of Thermal Expansion
10. Stress concentration at a crack tips
To improve fatigue life
Film Deposition
Griffith Crack Model
Electromigration
11. 1. Tensile (opening) 2. Sliding 3. Tearing
The three modes of crack surface displacement
Fatigue
Linewidth
Magnetic Storage Media Types
12. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Engineering Fracture Performance
Coefficient of Thermal Expansion
Transparent
Holloman Equation
13. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Soft Magnetic Materials
Diamagnetic Materials
Thermal Shock Resistance
Meissner Effect
14. # of thermally generated electrons = # of holes (broken bonds)
Magnetic Storage Media Types
Why fracture surfaces have faceted texture
Domains in Ferromagnetic & Ferrimagnetic Materials
Intrinsic Semiconductors
15. ...occurs in bcc metals but not in fcc metals.
Holloman Equation
Where does DBTT occur?
Elastic Deformation
Griffith Crack Model
16. Undergo extensive plastic deformation prior to failure.
IC Devices: P-N Rectifying Junction
Etching
Influence of Temperature on Magnetic Behavior
Ductile Materials
17. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Griffith Crack Model
Two ways to measure heat capacity
Yield and Reliability
Large Hardness
18. 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
Magnetic Storage
Plastic Deformation (Metals)
Ductile Materials
Stress Intensity Factor
19. 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.
Insulators
Opacifiers
Slip Bands
Why fracture surfaces have faceted texture
20. These materials are "attracted" to magnetic fields.
Paramagnetic Materials
Luminescence examples
IC Devices: P-N Rectifying Junction
Work Hardening
21. 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)
Electromigration
There is no perfect material?
Generation of a Magnetic Field - Vacuum
True Strain
22. 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
Metallization
Extrinsic Semiconductors
Incident Light
23. Ability to transmit a clear image - The image is clear.
True Stress
Impact - Toughness
Electromigration
Transparent
24. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Meissner Effect
Relative Permeability
Hard Magnetic Materials
Force Decomposition
25. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Paramagnetic Materials
Domains in Ferromagnetic & Ferrimagnetic Materials
Fourier's Law
Pure Semiconductors: Conductivity vs. T
26. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Elastic Deformation
How to gage the extent of plastic deformation
Metals: Resistivity vs. T - Impurities
Stages of Failure: Ductile Fracture
27. 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.
The Transistor
Scattering
Two ways to measure heat capacity
Hard Magnetic Materials
28. Because of ionic & covalent-type bonding.
Lithography
Hard Magnetic Materials
True Stress
Why do ceramics have larger bonding energy?
29. Cracks pass through grains - often along specific crystal planes.
Transgranular Fracture
Charpy or Izod test
Griffith Crack Model
LASER
30. 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
How to gage the extent of plastic deformation
Impact energy
Incident Light
Where does DBTT occur?
31. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
Why materials fail in service
Ductile-to-Brittle Transition
Pure Semiconductors: Conductivity vs. T
Why do ceramics have larger bonding energy?
32. Increase temperature - increase in interatomic separation - thermal expansion
Thermal Expansion: Asymmetric curve
LASER
Insulators
Color
33. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Dependence of Heat Capacity on Temperature
Critical Properties of Superconductive Materials
Metallization
Transparent
34. These materials are relatively unaffected by magnetic fields.
Brittle Ceramics
IC Devices: P-N Rectifying Junction
Diamagnetic Materials
Reflectance of Non-Metals
35. Sigma=ln(li/lo)
Stress Intensity Factor
True Strain
Reflection of Light for Metals
Yield and Reliability
36. Materials change size when temperature is changed
Stress Intensity Factor
Meissner Effect
Fatigue
Thermal expansion
37. A high index of refraction (n value) allows for multiple internal reactions.
Film Deposition
Hardness
Sparkle of Diamonds
Slip Bands
38. 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
Stages of Failure: Ductile Fracture
Two kinds of Reflection
Color
Oxidation
39. 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
Critical Properties of Superconductive Materials
Shear and Tensile Stress
Thermal Stresses
Generation of a Magnetic Field - Vacuum
40. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Paramagnetic Materials
Conduction & Electron Transport
Ductile Fracture
Rockwell
41. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Influence of Temperature on Magnetic Behavior
Intergranular Fracture
Coherent
Two kinds of Reflection
42. Is analogous to toughness.
Why fracture surfaces have faceted texture
Impact energy
Magnetic Storage Media Types
Fatigue
43. 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."
True Strain
Incident Light
Charpy or Izod test
Heat Capacity
44. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
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45. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Plastic Deformation (Metals)
Film Deposition
Not severe
How an LCD works
46. 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
Opacity
Two ways to measure heat capacity
Ductile-to-Brittle Transition
How an LCD works
47. Undergo little or no plastic deformation.
Rockwell
Brittle Materials
Why do ceramics have larger bonding energy?
The Transistor
48. Increase temperature - no increase in interatomic separation - no thermal expansion
Why fracture surfaces have faceted texture
Incoherent
Thermal Expansion: Symmetric curve
Stress Intensity values
49. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
What do magnetic moments arise from?
Reflectance of Non-Metals
Transgranular Fracture
Liquid Crystal Displays (LCD's)
50. A measure of the ease with which a B field can be induced inside a material.
Relative Permeability
Charpy or Izod test
M is known as what?
Conduction & Electron Transport