SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
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. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Scattering
Film Deposition
The Transistor
Force Decomposition
2. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Intrinsic Semiconductors
Generation of a Magnetic Field - Vacuum
Energy States: Insulators and Semiconductors
Where does DBTT occur?
3. Ability to transmit a clear image - The image is clear.
Luminescence examples
Liquid Crystal Displays (LCD's)
True Strain
Transparent
4. These materials are "attracted" to magnetic fields.
Griffith Crack Model
The Transistor
Intrinsic Semiconductors
Paramagnetic Materials
5. 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
High impact energy
Bending tests
Electrical Conduction
6. Increase temperature - increase in interatomic separation - thermal expansion
Transgranular Fracture
Thermal Shock Resistance
Thermal Expansion: Asymmetric curve
Valence band
7. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Domains in Ferromagnetic & Ferrimagnetic Materials
Sparkle of Diamonds
Translucent
Intrinsic Semiconductors
8. Occur when lots of dislocations move.
Response to a Magnetic Field
Slip Bands
Transgranular Fracture
Opaque
9. Sigma=ln(li/lo)
Meissner Effect
Energy States: Insulators and Semiconductors
True Strain
High impact energy
10. 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.
Plastic Deformation (Metals)
Relative Permeability
Oxidation
Stress Intensity Factor
11. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Sparkle of Diamonds
To improve fatigue life
Energy States: Insulators and Semiconductors
Charpy or Izod test
12. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Two kinds of Reflection
High impact energy
Domains in Ferromagnetic & Ferrimagnetic Materials
Force Decomposition
13. Elastic means reversible! This is not a permanent deformation.
Work Hardening
Hard Magnetic Materials
Stages of Failure: Ductile Fracture
Elastic Deformation
14. There is always some statistical distribution of flaws or defects.
Domains in Ferromagnetic & Ferrimagnetic Materials
There is no perfect material?
Conduction & Electron Transport
Impact - Toughness
15. 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."
Electrical Conduction
LASER
Charpy or Izod test
Reflection of Light for Metals
16. Second phase particles with n > glass.
Soft Magnetic Materials
Hysteresis and Permanent Magnetization
Metals: Resistivity vs. T - Impurities
Opacifiers
17. 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
Thermal Expansion: Symmetric curve
Influence of Temperature on Magnetic Behavior
Ductile Fracture
4 Types of Magnetism
18. 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.
Linewidth
M is known as what?
Heat Capacity from an Atomic Prospective
Force Decomposition
19. Width of smallest feature obtainable on Si surface
Linewidth
Electromigration
Two ways to measure heat capacity
Critical Properties of Superconductive Materials
20. Materials change size when temperature is changed
Thermal Shock Resistance
Sparkle of Diamonds
Valence band
Thermal expansion
21. ...occurs in bcc metals but not in fcc metals.
Generation of a Magnetic Field - Within a Solid Material
Opacity
Paramagnetic Materials
Where does DBTT occur?
22. Becomes harder (more strain) to stretch (elongate)
Force Decomposition
Work Hardening
Reflectance of Non-Metals
Linewidth
23. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Lithography
Diamagnetic Materials
Why fracture surfaces have faceted texture
Shear and Tensile Stress
24. Wet: isotropic - under cut Dry: ansiotropic - directional
Response to a Magnetic Field
M is known as what?
Meissner Effect
Etching
25. 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.
Etching
Internal magnetic moments
HB (Brinell Hardness)
Opacity
26. 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
To improve fatigue life
Why materials fail in service
27. 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
Heat Capacity
Coherent
Hysteresis and Permanent Magnetization
Engineering Fracture Performance
28. The size of the material changes with a change in temperature - polymers have the largest values
Coefficient of Thermal Expansion
Liquid Crystal Displays (LCD's)
Rockwell
Transgranular Fracture
29. 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
Insulators
Thermal Expansion: Asymmetric curve
LASER
30. These materials are relatively unaffected by magnetic fields.
Critical Properties of Superconductive Materials
Diamagnetic Materials
Rockwell
Coefficient of Thermal Expansion
31. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
There is no perfect material?
Magnetic Storage Media Types
Valence band
Brittle Fracture
32. Cracks propagate along grain boundaries.
Generation of a Magnetic Field - Within a Solid Material
Ductile Materials
Intergranular Fracture
Why fracture surfaces have faceted texture
33. 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
Scattering
Impact - Toughness
Rockwell
Energy States: Insulators and Semiconductors
34. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Conduction & Electron Transport
Shear and Tensile Stress
Influence of Temperature on Magnetic Behavior
Modulus of Rupture (MOR)
35. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Coefficient of Thermal Expansion
Incoherent
How to gage the extent of plastic deformation
Transgranular Fracture
36. Rho=F/A - tau=G/A . Depending on what angle the force is applied - and what angle the crystal is at - it takes different amounts of force to induce plastic deformation.
The three modes of crack surface displacement
True Stress
Insulators
Shear and Tensile Stress
37. 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.
Slip Bands
Opaque
Iron-Silicon Alloy in Transformer Cores
Impact - Toughness
38. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Incoherent
4 Types of Magnetism
What do magnetic moments arise from?
Electrical Conduction
39. The ability of a material to transport heat - Atomic Perspective: Atomic vibrations and free electrons in hotter regions transport energy to cooler regions - Metals have the largest values
Translucent
Coherent
Thermal Conductivity
Generation of a Magnetic Field - Vacuum
40. - 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
Work Hardening
Hard Magnetic Materials
Luminescence
IC Devices: P-N Rectifying Junction
41. High toughness; material resists crack propagation.
High impact energy
Opacifiers
Domains in Ferromagnetic & Ferrimagnetic Materials
Stress Intensity Factor
42. They are used to assess properties of ceramics & glasses.
Bending tests
Reflection of Light for Metals
True Strain
4 Types of Magnetism
43. Measures Hardness - No major sample damage - Each scales runs to 130 but only useful in range 20-100 - Minor load is 10 kg - Major load: 60 kg (diamond) - 100 kg (1/16 in. ball) - 150 kg (diamond)
Extrinsic Semiconductors
Stress Intensity Factor
Incoherent
Rockwell
44. Digitalized data in the form of electrical signals are transferred to and recorded digitally on a magnetic medium (tape or disk) - This transference is accomplished by a recording system that consists of a read/write head - "write" or record data by
Dependence of Heat Capacity on Temperature
Magnetic Storage
Electrical Conduction
Ductile Materials
45. Ohms Law: voltage drop = current * resistance
Incident Light
Paramagnetic Materials
Electrical Conduction
Brittle Materials
46. 1. Tensile (opening) 2. Sliding 3. Tearing
Elastic Deformation
The three modes of crack surface displacement
Valence band
Thermal Conductivity
47. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Pure Semiconductors: Conductivity vs. T
Opacifiers
Thermal Conductivity
Why materials fail in service
48. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Holloman Equation
Impact - Toughness
Fatigue
Internal magnetic moments
49. Undergo little or no plastic deformation.
Engineering Fracture Performance
Brittle Materials
Coherent
Refraction
50. A measure of the ease with which a B field can be induced inside a material.
Ductile Materials
Magnetic Storage
Relative Permeability
Critical Properties of Superconductive Materials