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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. 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
How to gage the extent of plastic deformation
Force Decomposition
Two ways to measure heat capacity
2. 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
Plastic Deformation (Metals)
Fatigue
Coefficient of Thermal Expansion
Reflection of Light for Metals
3. 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)
Bending tests
Generation of a Magnetic Field - Vacuum
Ductile Fracture
Hard Magnetic Materials
4. ...occurs in bcc metals but not in fcc metals.
4 Types of Magnetism
Thermal Conductivity
How an LCD works
Where does DBTT occur?
5. 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
Lithography
The Transistor
Opacifiers
How to gage the extent of plastic deformation
6. 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.
Slip Bands
Reflectance of Non-Metals
Generation of a Magnetic Field - Within a Solid Material
Lithography
7. 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
Thermal Expansion: Asymmetric curve
How to gage the extent of plastic deformation
Stages of Failure: Ductile Fracture
Liquid Crystal Displays (LCD's)
8. These materials are relatively unaffected by magnetic fields.
Fourier's Law
Diamagnetic Materials
Thermal Expansion: Symmetric curve
Not severe
9. Process by which metal atoms diffuse because of a potential.
Sparkle of Diamonds
Electromigration
Brittle Materials
Fourier's Law
10. A high index of refraction (n value) allows for multiple internal reactions.
Slip Bands
Two ways to measure heat capacity
Soft Magnetic Materials
Sparkle of Diamonds
11. Resistance to plastic deformation of cracking in compression - and better wear properties.
Insulators
Elastic Deformation
Large Hardness
LASER
12. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Reflectance of Non-Metals
Incoherent
Where does DBTT occur?
Thermal Expansion: Asymmetric curve
13. 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
LASER
Yield and Reliability
Thermal Stresses
14. Undergo extensive plastic deformation prior to failure.
Magnetic Storage Media Types
Luminescence
Ductile Materials
Metallization
15. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Ductile Fracture
To improve fatigue life
Magnetic Storage Media Types
Intergranular Fracture
16. Elastic means reversible! This is not a permanent deformation.
Stress Intensity Factor
Brittle Fracture
Elastic Deformation
Heat Capacity from an Atomic Prospective
17. High toughness; material resists crack propagation.
Bending tests
Film Deposition
High impact energy
Metals: Resistivity vs. T - Impurities
18. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Influence of Temperature on Magnetic Behavior
Plastic Deformation (Metals)
Intrinsic Semiconductors
Superconductivity
19. 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
Elastic Deformation
Oxidation
Magnetic Storage Media Types
20. 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.
Metallization
Pure Semiconductors: Conductivity vs. T
Heat Capacity
Luminescence examples
21. 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.
Superconductivity
The three modes of crack surface displacement
Insulators
Why fracture surfaces have faceted texture
22. Wet: isotropic - under cut Dry: ansiotropic - directional
Influence of Temperature on Magnetic Behavior
Domains in Ferromagnetic & Ferrimagnetic Materials
Etching
How to gage the extent of plastic deformation
23. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Thermal Stresses
The three modes of crack surface displacement
Thermal Shock Resistance
Why materials fail in service
24. 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."
Where does DBTT occur?
Force Decomposition
Charpy or Izod test
Ductile Materials
25. Sigma=ln(li/lo)
True Strain
Slip Bands
Ductile Fracture
Refraction
26. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Metals: Resistivity vs. T - Impurities
M is known as what?
Thermal expansion
Etching
27. 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.
Hysteresis and Permanent Magnetization
Heat Capacity
Specific Heat
Transparent
28. Occur when lots of dislocations move.
Relative Permeability
Influence of Temperature on Magnetic Behavior
Slip Bands
Luminescence
29. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Bending tests
Engineering Fracture Performance
Intergranular Fracture
Response to a Magnetic Field
30. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Valence band
Conduction & Electron Transport
Thermal Expansion: Symmetric curve
Force Decomposition
31. For a metal - there is no ______ - only reflection
LASER
Refraction
Reflection of Light for Metals
Force Decomposition
32. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Griffith Crack Model
Why fracture surfaces have faceted texture
Extrinsic Semiconductors
Why do ceramics have larger bonding energy?
33. 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.
Stress Intensity values
Superconductivity
Brittle Ceramics
Generation of a Magnetic Field - Vacuum
34. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Griffith Crack Model
4 Types of Magnetism
Stress Intensity values
Lithography
35. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Superconductivity
Luminescence
Heat Capacity from an Atomic Prospective
Critical Properties of Superconductive Materials
36. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Soft Magnetic Materials
Fourier's Law
Coherent
Magnetic Storage
37. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
To improve fatigue life
Two kinds of Reflection
Force Decomposition
HB (Brinell Hardness)
38. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Reflectance of Non-Metals
Intrinsic Semiconductors
Brittle Fracture
Stress Intensity Factor
39. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Opacity
What do magnetic moments arise from?
Lithography
Dependence of Heat Capacity on Temperature
40. Diffuse image
High impact energy
Translucent
Thermal Expansion: Symmetric curve
Stress Intensity Factor
41. Second phase particles with n > glass.
Hysteresis and Permanent Magnetization
Opacifiers
Liquid Crystal Displays (LCD's)
Force Decomposition
42. Transformer cores require soft magnetic materials - which are easily magnetized and de-magnetized - and have high electrical resistivity - Energy losses in transformers could be minimized if their cores were fabricated such that the easy magnetizatio
Energy States: Insulators and Semiconductors
Why fracture surfaces have faceted texture
4 Types of Magnetism
Iron-Silicon Alloy in Transformer Cores
43. These materials are "attracted" to magnetic fields.
Diamagnetic Materials
Paramagnetic Materials
Reflectance of Non-Metals
Response to a Magnetic Field
44. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Paramagnetic Materials
M is known as what?
Incoherent
Fatigue
45. 1. Tensile (opening) 2. Sliding 3. Tearing
Paramagnetic Materials
The three modes of crack surface displacement
Luminescence examples
True Stress
46. Is analogous to toughness.
Impact energy
Conduction & Electron Transport
Ductile Fracture
Brittle Materials
47. Because of ionic & covalent-type bonding.
Impact energy
Transgranular Fracture
Heat Capacity from an Atomic Prospective
Why do ceramics have larger bonding energy?
48. 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
Refraction
Why fracture surfaces have faceted texture
Why do ceramics have larger bonding energy?
Hysteresis and Permanent Magnetization
49. 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.
Influence of Temperature on Magnetic Behavior
Brittle Materials
Hardness
Opaque
50. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Ductile Fracture
Force Decomposition
Domains in Ferromagnetic & Ferrimagnetic Materials
Refraction