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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. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Influence of Temperature on Magnetic Behavior
Incoherent
Engineering Fracture Performance
Modulus of Rupture (MOR)
2. A high index of refraction (n value) allows for multiple internal reactions.
Holloman Equation
Superconductivity
Sparkle of Diamonds
Ductile-to-Brittle Transition
3. 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.
Charpy or Izod test
Internal magnetic moments
Critical Properties of Superconductive Materials
Insulators
4. 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
Reflection of Light for Metals
Thermal Expansion: Asymmetric curve
Thermal Conductivity
Generation of a Magnetic Field - Within a Solid Material
5. These materials are relatively unaffected by magnetic fields.
Brittle Materials
Diamagnetic Materials
Translucent
Slip Bands
6. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Thermal Expansion: Symmetric curve
Impact energy
HB (Brinell Hardness)
Intergranular Fracture
7. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Film Deposition
High impact energy
Response to a Magnetic Field
Metallization
8. A measure of the ease with which a B field can be induced inside a material.
Holloman Equation
Paramagnetic Materials
Relative Permeability
HB (Brinell Hardness)
9. 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.
IC Devices: P-N Rectifying Junction
Two ways to measure heat capacity
Stress Intensity Factor
Plastic Deformation (Metals)
10. These materials are "attracted" to magnetic fields.
Paramagnetic Materials
Brittle Fracture
Sparkle of Diamonds
Thermal Stresses
11. 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
How an LCD works
Heat Capacity
Slip Bands
12. 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.
Coherent
Two kinds of Reflection
Scattering
Electrical Conduction
13. ...occurs in bcc metals but not in fcc metals.
Liquid Crystal Displays (LCD's)
Metallization
Oxidation
Where does DBTT occur?
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.
Metallization
Opacity
Fatigue
Modulus of Rupture (MOR)
15. Wet: isotropic - under cut Dry: ansiotropic - directional
Etching
Luminescence
Impact - Toughness
There is no perfect material?
16. Undergo extensive plastic deformation prior to failure.
Pure Semiconductors: Conductivity vs. T
Ductile Materials
Specific Heat
Modulus of Rupture (MOR)
17. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
18. Width of smallest feature obtainable on Si surface
Linewidth
Modulus of Rupture (MOR)
Brittle Materials
Meissner Effect
19. Becomes harder (more strain) to stretch (elongate)
Holloman Equation
Two ways to measure heat capacity
Work Hardening
Stress Intensity Factor
20. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
True Stress
Modulus of Rupture (MOR)
Brittle Materials
Two kinds of Reflection
21. 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.
Shear and Tensile Stress
Reflectance of Non-Metals
Generation of a Magnetic Field - Within a Solid Material
Dependence of Heat Capacity on Temperature
22. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Holloman Equation
The Transistor
What do magnetic moments arise from?
Sparkle of Diamonds
23. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
High impact energy
Fourier's Law
Soft Magnetic Materials
Fatigue
24. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Extrinsic Semiconductors
Stress Intensity Factor
Modulus of Rupture (MOR)
Griffith Crack Model
25. 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
Plastic Deformation (Metals)
Response to a Magnetic Field
Luminescence examples
How an LCD works
26. 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."
Charpy or Izod test
Reflectance of Non-Metals
LASER
HB (Brinell Hardness)
27. If a material has ________ - then the field generated by those moments must be added to the induced field.
Internal magnetic moments
Stages of Failure: Ductile Fracture
Paramagnetic Materials
Intrinsic Semiconductors
28. 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
Valence band
Insulators
Iron-Silicon Alloy in Transformer Cores
Thermal Expansion: Asymmetric curve
29. 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
Conduction & Electron Transport
Hysteresis and Permanent Magnetization
Incident Light
Impact - Toughness
30. - 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
Superconductivity
Why fracture surfaces have faceted texture
Holloman Equation
Stress Intensity values
31. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Why fracture surfaces have faceted texture
Luminescence examples
Dependence of Heat Capacity on Temperature
Superconductivity
32. Increase temperature - increase in interatomic separation - thermal expansion
Coherent
Thermal Expansion: Asymmetric curve
Thermal expansion
Domains in Ferromagnetic & Ferrimagnetic Materials
33. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
To improve fatigue life
Incident Light
Impact - Toughness
Energy States: Insulators and Semiconductors
34. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Liquid Crystal Displays (LCD's)
Scattering
Where does DBTT occur?
Energy States: Insulators and Semiconductors
35. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Work Hardening
Translucent
Incident Light
Holloman Equation
36. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Ductile Fracture
Domains in Ferromagnetic & Ferrimagnetic Materials
True Strain
Modulus of Rupture (MOR)
37. 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)
Oxidation
Shear and Tensile Stress
Griffith Crack Model
Generation of a Magnetic Field - Vacuum
38. Cracks pass through grains - often along specific crystal planes.
Impact - Toughness
Two ways to measure heat capacity
Transgranular Fracture
Extrinsic Semiconductors
39. For a metal - there is no ______ - only reflection
Stress Intensity Factor
Domains in Ferromagnetic & Ferrimagnetic Materials
Opaque
Refraction
40. Elastic means reversible! This is not a permanent deformation.
Specific Heat
Refraction
Fourier's Law
Elastic Deformation
41. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Thermal Stresses
Superconductivity
How an LCD works
Influence of Temperature on Magnetic Behavior
42. High toughness; material resists crack propagation.
Two ways to measure heat capacity
Relative Permeability
High impact energy
Fourier's Law
43. 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
Rockwell
Stages of Failure: Ductile Fracture
Charpy or Izod test
Impact - Toughness
44. Undergo little or no plastic deformation.
IC Devices: P-N Rectifying Junction
Heat Capacity
Brittle Materials
Relative Permeability
45. 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
High impact energy
Why materials fail in service
Metallization
46. 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.
Energy States: Insulators and Semiconductors
Brittle Ceramics
Thermal Expansion: Symmetric curve
Pure Semiconductors: Conductivity vs. T
47. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Influence of Temperature on Magnetic Behavior
Magnetic Storage
To improve fatigue life
Thermal Stresses
48. Metals are good conductors since their _______is only partially filled.
Hardness
Refraction
Valence band
Thermal Conductivity
49. 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
IC Devices: P-N Rectifying Junction
Thermal Expansion: Asymmetric curve
Reflection of Light for Metals
Why fracture surfaces have faceted texture
50. Stress concentration at a crack tips
Incoherent
High impact energy
Griffith Crack Model
Impact energy