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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. Light Amplification by Stimulated Emission of Radiation
Film Deposition
LASER
Generation of a Magnetic Field - Within a Solid Material
Electrical Conduction
2. Is analogous to toughness.
Impact energy
Refraction
Ductile-to-Brittle Transition
Thermal Conductivity
3. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Luminescence examples
Stress Intensity values
Holloman Equation
Opaque
4. 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
Hysteresis and Permanent Magnetization
LASER
Elastic Deformation
Refraction
5. A high index of refraction (n value) allows for multiple internal reactions.
Intrinsic Semiconductors
Sparkle of Diamonds
Thermal expansion
Engineering Fracture Performance
6. 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.
Pure Semiconductors: Conductivity vs. T
Brittle Ceramics
To improve fatigue life
Heat Capacity
7. Undergo extensive plastic deformation prior to failure.
Ductile Materials
Response to a Magnetic Field
The Transistor
Why fracture surfaces have faceted texture
8. 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)
Engineering Fracture Performance
Generation of a Magnetic Field - Vacuum
Charpy or Izod test
Dependence of Heat Capacity on Temperature
9. 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
Transgranular Fracture
Response to a Magnetic Field
Film Deposition
How an LCD works
10. The ability of a material to be rapidly cooled and not fracture
Hysteresis and Permanent Magnetization
Fourier's Law
Thermal Shock Resistance
Energy States: Insulators and Semiconductors
11. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Where does DBTT occur?
Luminescence examples
Influence of Temperature on Magnetic Behavior
Response to a Magnetic Field
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
Intrinsic Semiconductors
The Transistor
Heat Capacity from an Atomic Prospective
Etching
13. Occur when lots of dislocations move.
Coherent
True Strain
Slip Bands
IC Devices: P-N Rectifying Junction
14. These materials are "attracted" to magnetic fields.
Paramagnetic Materials
Color
Two ways to measure heat capacity
True Strain
15. 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.
Metals: Resistivity vs. T - Impurities
Translucent
Heat Capacity from an Atomic Prospective
Plastic Deformation (Metals)
16. Different orientation of cleavage planes in grains.
Opaque
Brittle Fracture
Why fracture surfaces have faceted texture
M is known as what?
17. High toughness; material resists crack propagation.
Metallization
Valence band
High impact energy
There is no perfect material?
18. Becomes harder (more strain) to stretch (elongate)
Paramagnetic Materials
The Transistor
Work Hardening
Soft Magnetic Materials
19. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Extrinsic Semiconductors
Reflection of Light for Metals
Why fracture surfaces have faceted texture
Brittle Ceramics
20. ...occurs in bcc metals but not in fcc metals.
Where does DBTT occur?
Transgranular Fracture
Charpy or Izod test
Reflection of Light for Metals
21. 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
Fatigue
Thermal Stresses
Film Deposition
Iron-Silicon Alloy in Transformer Cores
22. 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.
Impact - Toughness
Domains in Ferromagnetic & Ferrimagnetic Materials
Lithography
Luminescence examples
23. Diffuse image
Holloman Equation
Plastic Deformation (Metals)
Valence band
Translucent
24. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Transparent
Force Decomposition
Intrinsic Semiconductors
What do magnetic moments arise from?
25. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Heat Capacity
Conduction & Electron Transport
Stress Intensity values
Electrical Conduction
26. 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
High impact energy
Coherent
True Strain
27. Increase temperature - increase in interatomic separation - thermal expansion
Superconductivity
Generation of a Magnetic Field - Within a Solid Material
Thermal Expansion: Asymmetric curve
Intrinsic Semiconductors
28. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Meissner Effect
Extrinsic Semiconductors
There is no perfect material?
Why materials fail in service
29. There is always some statistical distribution of flaws or defects.
There is no perfect material?
Charpy or Izod test
Why do ceramics have larger bonding energy?
Linewidth
30. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Transgranular Fracture
Modulus of Rupture (MOR)
Heat Capacity from an Atomic Prospective
Ductile Materials
31. 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.
Refraction
Heat Capacity
Opaque
Critical Properties of Superconductive Materials
32. 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
Paramagnetic Materials
Impact - Toughness
Conduction & Electron Transport
Brittle Fracture
33. Without passing a current a continually varying magnetic field will cause a current to flow
Shear and Tensile Stress
Heat Capacity from an Atomic Prospective
Response to a Magnetic Field
Hardness
34. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Thermal Stresses
Generation of a Magnetic Field - Vacuum
Coherent
Engineering Fracture Performance
35. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Critical Properties of Superconductive Materials
Extrinsic Semiconductors
Influence of Temperature on Magnetic Behavior
Film Deposition
36. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Ductile Fracture
Force Decomposition
Scattering
To improve fatigue life
37. 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.
4 Types of Magnetism
Internal magnetic moments
Lithography
Scattering
38. Typical loading conditions are _____ enough to break all inter-atomic bonds
Luminescence
To improve fatigue life
Not severe
Energy States: Insulators and Semiconductors
39. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Metallization
Thermal expansion
True Strain
Domains in Ferromagnetic & Ferrimagnetic Materials
40. 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
What do magnetic moments arise from?
Critical Properties of Superconductive Materials
Iron-Silicon Alloy in Transformer Cores
Dependence of Heat Capacity on Temperature
41. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
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42. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Where does DBTT occur?
Valence band
Ductile Fracture
Opacity
43. 1. Diamagnetic (Xm ~ 10^-5) - small and negative magnetic susceptibilities 2. Paramagnetic (Xm ~ 10^-4) - small and positive magnetic susceptibilities 3. Ferromagnetic - large magnetic susceptibilities 4. Ferrimagnetic (Xm as large as 10^6) - large m
4 Types of Magnetism
Intrinsic Semiconductors
Paramagnetic Materials
Pure Semiconductors: Conductivity vs. T
44. 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."
What do magnetic moments arise from?
Elastic Deformation
Stages of Failure: Ductile Fracture
Charpy or Izod test
45. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Opacifiers
Energy States: Insulators and Semiconductors
Response to a Magnetic Field
Fatigue
46. They are used to assess properties of ceramics & glasses.
4 Types of Magnetism
Thermal expansion
Bending tests
Opacity
47. Metals are good conductors since their _______is only partially filled.
Valence band
Heat Capacity from an Atomic Prospective
Dependence of Heat Capacity on Temperature
IC Devices: P-N Rectifying Junction
48. 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
Iron-Silicon Alloy in Transformer Cores
Slip Bands
Oxidation
True Strain
49. 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
Hysteresis and Permanent Magnetization
IC Devices: P-N Rectifying Junction
Impact - Toughness
50. Process by which metal atoms diffuse because of a potential.
Electromigration
Opacity
Fourier's Law
Stress Intensity Factor