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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. 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
Meissner Effect
Influence of Temperature on Magnetic Behavior
Specific Heat
2. 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
Why do ceramics have larger bonding energy?
Conduction & Electron Transport
Specific Heat
3. 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.
Griffith Crack Model
Specific Heat
Stages of Failure: Ductile Fracture
Brittle Ceramics
4. Cracks pass through grains - often along specific crystal planes.
Incident Light
Hardness
Transgranular Fracture
Brittle Fracture
5. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Transgranular Fracture
Holloman Equation
IC Devices: P-N Rectifying Junction
Linewidth
6. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Metallization
Film Deposition
Linewidth
Fourier's Law
7. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Why materials fail in service
HB (Brinell Hardness)
How to gage the extent of plastic deformation
Incident Light
8. 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.
Energy States: Insulators and Semiconductors
Oxidation
Opacity
Slip Bands
9. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Critical Properties of Superconductive Materials
Elastic Deformation
Generation of a Magnetic Field - Within a Solid Material
Generation of a Magnetic Field - Vacuum
10. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Metals: Resistivity vs. T - Impurities
Paramagnetic Materials
Domains in Ferromagnetic & Ferrimagnetic Materials
Bending tests
11. Stress concentration at a crack tips
Transparent
IC Devices: P-N Rectifying Junction
Griffith Crack Model
Electromigration
12. The size of the material changes with a change in temperature - polymers have the largest values
Slip Bands
Lithography
Coefficient of Thermal Expansion
How to gage the extent of plastic deformation
13. Metals are good conductors since their _______is only partially filled.
Meissner Effect
Valence band
Linewidth
Transgranular Fracture
14. Typical loading conditions are _____ enough to break all inter-atomic bonds
Not severe
Thermal expansion
Hardness
Impact energy
15. Occur when lots of dislocations move.
Insulators
Metallization
Stress Intensity Factor
Slip Bands
16. Elastic means reversible! This is not a permanent deformation.
Electrical Conduction
Iron-Silicon Alloy in Transformer Cores
Coherent
Elastic Deformation
17. Process by which metal atoms diffuse because of a potential.
Elastic Deformation
Heat Capacity
Incident Light
Electromigration
18. 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)
Thermal expansion
There is no perfect material?
Magnetic Storage Media Types
Generation of a Magnetic Field - Vacuum
19. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Coherent
Metals: Resistivity vs. T - Impurities
Generation of a Magnetic Field - Vacuum
Engineering Fracture Performance
20. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
To improve fatigue life
There is no perfect material?
Two kinds of Reflection
Opaque
21. Emitted light is in phase
Brittle Ceramics
Fourier's Law
Coherent
Critical Properties of Superconductive Materials
22. - 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
Heat Capacity from an Atomic Prospective
What do magnetic moments arise from?
Transparent
23. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Thermal expansion
Soft Magnetic Materials
Modulus of Rupture (MOR)
Transgranular Fracture
24. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Soft Magnetic Materials
Transparent
Brittle Ceramics
Lithography
25. ...occurs in bcc metals but not in fcc metals.
Engineering Fracture Performance
Critical Properties of Superconductive Materials
Where does DBTT occur?
Brittle Ceramics
26. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Conduction & Electron Transport
Oxidation
Magnetic Storage Media Types
Ductile Fracture
27. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Transgranular Fracture
Extrinsic Semiconductors
Metallization
Influence of Temperature on Magnetic Behavior
28. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Extrinsic Semiconductors
Work Hardening
Reflection of Light for Metals
High impact energy
29. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
Charpy or Izod test
Generation of a Magnetic Field - Within a Solid Material
Meissner Effect
What do magnetic moments arise from?
30. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Insulators
Stress Intensity Factor
Pure Semiconductors: Conductivity vs. T
How to gage the extent of plastic deformation
31. 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 values
Generation of a Magnetic Field - Vacuum
Where does DBTT occur?
Stress Intensity Factor
32. Another optical property - Depends on the wavelength of the visible spectrum.
Griffith Crack Model
Luminescence examples
Hard Magnetic Materials
Color
33. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION
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34. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Brittle Materials
Fatigue
Brittle Fracture
Generation of a Magnetic Field - Vacuum
35. These materials are "attracted" to magnetic fields.
Electromigration
Impact energy
Paramagnetic Materials
Thermal Expansion: Asymmetric curve
36. Materials change size when temperature is changed
Thermal expansion
M is known as what?
There is no perfect material?
Shear and Tensile Stress
37. 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
Extrinsic Semiconductors
Two kinds of Reflection
How to gage the extent of plastic deformation
Reflection of Light for Metals
38. 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
Oxidation
Refraction
Paramagnetic Materials
Two kinds of Reflection
39. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Fatigue
Transparent
Luminescence examples
Thermal Stresses
40. These materials are relatively unaffected by magnetic fields.
Thermal Conductivity
Diamagnetic Materials
There is no perfect material?
Ductile Materials
41. A high index of refraction (n value) allows for multiple internal reactions.
Why do ceramics have larger bonding energy?
Sparkle of Diamonds
Metallization
Translucent
42. Different orientation of cleavage planes in grains.
Stress Intensity Factor
Why fracture surfaces have faceted texture
Brittle Materials
Reflectance of Non-Metals
43. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Two ways to measure heat capacity
Soft Magnetic Materials
Stages of Failure: Ductile Fracture
Where does DBTT occur?
44. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
Iron-Silicon Alloy in Transformer Cores
Pure Semiconductors: Conductivity vs. T
Ductile-to-Brittle Transition
Energy States: Insulators and Semiconductors
45. 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
Stress Intensity values
What do magnetic moments arise from?
Two ways to measure heat capacity
46. Becomes harder (more strain) to stretch (elongate)
Domains in Ferromagnetic & Ferrimagnetic Materials
Work Hardening
Plastic Deformation (Metals)
Heat Capacity
47. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Hard Magnetic Materials
Luminescence examples
Insulators
4 Types of Magnetism
48. Specific heat = energy input/(mass*temperature change)
Hard Magnetic Materials
Specific Heat
Heat Capacity
What do magnetic moments arise from?
49. A measure of the ease with which a B field can be induced inside a material.
Relative Permeability
Thermal Expansion: Symmetric curve
Shear and Tensile Stress
Translucent
50. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Why materials fail in service
Influence of Temperature on Magnetic Behavior
Generation of a Magnetic Field - Vacuum
The Transistor