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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. A high index of refraction (n value) allows for multiple internal reactions.
There is no perfect material?
Sparkle of Diamonds
Hard Magnetic Materials
Relative Permeability
2. Elastic means reversible! This is not a permanent deformation.
Reflectance of Non-Metals
High impact energy
Elastic Deformation
Stress Intensity Factor
3. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Energy States: Insulators and Semiconductors
Plastic Deformation (Metals)
Film Deposition
Transparent
4. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
IC Devices: P-N Rectifying Junction
Extrinsic Semiconductors
The three modes of crack surface displacement
Translucent
5. 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
Internal magnetic moments
Stress Intensity values
How to gage the extent of plastic deformation
Thermal Shock Resistance
6. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Thermal Expansion: Symmetric curve
Meissner Effect
Engineering Fracture Performance
Insulators
7. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Force Decomposition
Generation of a Magnetic Field - Within a Solid Material
LASER
Reflection of Light for Metals
8. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
To improve fatigue life
Meissner Effect
Stages of Failure: Ductile Fracture
Superconductivity
9. There is always some statistical distribution of flaws or defects.
Bending tests
Meissner Effect
There is no perfect material?
Sparkle of Diamonds
10. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
What do magnetic moments arise from?
Generation of a Magnetic Field - Within a Solid Material
Yield and Reliability
Brittle Fracture
11. Process by which metal atoms diffuse because of a potential.
Hardness
Refraction
Elastic Deformation
Electromigration
12. 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
Two ways to measure heat capacity
True Stress
Brittle Fracture
Thermal Conductivity
13. 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.
Electromigration
Opaque
Influence of Temperature on Magnetic Behavior
Fourier's Law
14. 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.
Opacity
4 Types of Magnetism
Sparkle of Diamonds
Dependence of Heat Capacity on Temperature
15. 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
Diamagnetic Materials
Opaque
Large Hardness
16. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Thermal Expansion: Symmetric curve
Influence of Temperature on Magnetic Behavior
Metals: Resistivity vs. T - Impurities
Dependence of Heat Capacity on Temperature
17. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
Sparkle of Diamonds
Magnetic Storage
Internal magnetic moments
Ductile-to-Brittle Transition
18. Materials change size when temperature is changed
To improve fatigue life
Work Hardening
Response to a Magnetic Field
Thermal expansion
19. They are used to assess properties of ceramics & glasses.
Griffith Crack Model
Hardness
Two kinds of Reflection
Bending tests
20. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Stress Intensity Factor
To improve fatigue life
Hard Magnetic Materials
Rockwell
21. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Thermal Expansion: Symmetric curve
True Stress
Holloman Equation
Lithography
22. Emitted light is in phase
Heat Capacity from an Atomic Prospective
Insulators
Coherent
Transgranular Fracture
23. Is analogous to toughness.
Plastic Deformation (Metals)
Soft Magnetic Materials
Refraction
Impact energy
24. - Metals that exhibit high ductility - exhibit high toughness. Ceramics are very strong - but have low ductility and low toughness - Polymers are very ductile but are not generally very strong in shear (compared to metals and ceramics). They have low
Stress Intensity values
Hysteresis and Permanent Magnetization
True Strain
To improve fatigue life
25. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
M is known as what?
To improve fatigue life
Stress Intensity Factor
4 Types of Magnetism
26. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Elastic Deformation
Film Deposition
Magnetic Storage Media Types
Ductile Fracture
27. - 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
Metallization
Luminescence
Not severe
Thermal Stresses
28. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Lithography
LASER
Thermal Conductivity
Relative Permeability
29. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Elastic Deformation
Heat Capacity from an Atomic Prospective
Why materials fail in service
True Stress
30. 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
Where does DBTT occur?
Intrinsic Semiconductors
Superconductivity
Stress Intensity Factor
31. Increase temperature - increase in interatomic separation - thermal expansion
Linewidth
Metals: Resistivity vs. T - Impurities
Thermal Expansion: Asymmetric curve
Engineering Fracture Performance
32. 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.
Iron-Silicon Alloy in Transformer Cores
Shear and Tensile Stress
Incoherent
Why fracture surfaces have faceted texture
33. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Holloman Equation
Thermal Stresses
Response to a Magnetic Field
Conduction & Electron Transport
34. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Where does DBTT occur?
Soft Magnetic Materials
To improve fatigue life
Engineering Fracture Performance
35. Cracks propagate along grain boundaries.
There is no perfect material?
Response to a Magnetic Field
Intergranular Fracture
Reflectance of Non-Metals
36. ...occurs in bcc metals but not in fcc metals.
Where does DBTT occur?
Elastic Deformation
Thermal Stresses
Coherent
37. Because of ionic & covalent-type bonding.
M is known as what?
Dependence of Heat Capacity on Temperature
Why do ceramics have larger bonding energy?
Charpy or Izod test
38. 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
Scattering
M is known as what?
The Transistor
Incident Light
39. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Insulators
Ductile Fracture
Heat Capacity
The Transistor
40. Sigma=ln(li/lo)
Energy States: Insulators and Semiconductors
Iron-Silicon Alloy in Transformer Cores
Not severe
True Strain
41. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Generation of a Magnetic Field - Within a Solid Material
Transgranular Fracture
Liquid Crystal Displays (LCD's)
Superconductivity
42. 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
Shear and Tensile Stress
Magnetic Storage
There is no perfect material?
Domains in Ferromagnetic & Ferrimagnetic Materials
43. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
HB (Brinell Hardness)
Heat Capacity
Stages of Failure: Ductile Fracture
There is no perfect material?
44. 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
Heat Capacity from an Atomic Prospective
Heat Capacity
Transgranular Fracture
Reflection of Light for Metals
45. Metals are good conductors since their _______is only partially filled.
Stress Intensity Factor
Liquid Crystal Displays (LCD's)
Valence band
Why materials fail in service
46. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Dependence of Heat Capacity on Temperature
Electromigration
Large Hardness
Incident Light
47. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Dependence of Heat Capacity on Temperature
Heat Capacity
HB (Brinell Hardness)
Opaque
48. Ability to transmit a clear image - The image is clear.
Transparent
Lithography
Impact energy
Holloman Equation
49. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Modulus of Rupture (MOR)
Refraction
Work Hardening
Large Hardness
50. Becomes harder (more strain) to stretch (elongate)
Scattering
High impact energy
Work Hardening
Engineering Fracture Performance