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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 magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Coefficient of Thermal Expansion
To improve fatigue life
Generation of a Magnetic Field - Within a Solid Material
Meissner Effect
2. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Why fracture surfaces have faceted texture
Metallization
Magnetic Storage Media Types
Intrinsic Semiconductors
3. Light Amplification by Stimulated Emission of Radiation
Luminescence
Why do ceramics have larger bonding energy?
LASER
How an LCD works
4. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Etching
Charpy or Izod test
Force Decomposition
Critical Properties of Superconductive Materials
5. Cracks pass through grains - often along specific crystal planes.
Electromigration
Pure Semiconductors: Conductivity vs. T
Transgranular Fracture
Thermal expansion
6. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Extrinsic Semiconductors
Ductile Materials
Hard Magnetic Materials
Refraction
7. 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
Brittle Ceramics
Thermal Expansion: Asymmetric curve
Color
8. 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.
Brittle Ceramics
Scattering
Luminescence examples
Magnetic Storage Media Types
9. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Transparent
Luminescence
Heat Capacity from an Atomic Prospective
Generation of a Magnetic Field - Vacuum
10. Not ALL the light is refracted - SOME is reflected. Materials with a high index of refraction also have high reflectance - High R is bad for lens applications - since this leads to undesirable light losses or interference.
Brittle Ceramics
Reflectance of Non-Metals
Hysteresis and Permanent Magnetization
Holloman Equation
11. 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.
Dependence of Heat Capacity on Temperature
Metals: Resistivity vs. T - Impurities
Opacity
Coherent
12. The ability of a material to be rapidly cooled and not fracture
Insulators
Thermal Shock Resistance
Magnetic Storage Media Types
What do magnetic moments arise from?
13. 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
Soft Magnetic Materials
Thermal Expansion: Asymmetric curve
True Stress
14. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Refraction
Magnetic Storage
Stages of Failure: Ductile Fracture
The three modes of crack surface displacement
15. 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
Ductile-to-Brittle Transition
Heat Capacity
Iron-Silicon Alloy in Transformer Cores
16. 1. Yield = ratio of functional chips to total # of chips - Most yield loss during wafer processing - b/c of complex 2. Reliability - No device has infinite lifetime. Statistical methods to predict expected lifetime - Failure mechanisms: Diffusion reg
The three modes of crack surface displacement
Large Hardness
Fourier's Law
Yield and Reliability
17. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Hard Magnetic Materials
Brittle Fracture
Diamagnetic Materials
Dependence of Heat Capacity on Temperature
18. If a material has ________ - then the field generated by those moments must be added to the induced field.
Internal magnetic moments
To improve fatigue life
Soft Magnetic Materials
Brittle Materials
19. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
LASER
IC Devices: P-N Rectifying Junction
Fatigue
Thermal Stresses
20. 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
Brittle Fracture
Valence band
True Strain
Impact - Toughness
21. 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)
Work Hardening
Refraction
Stress Intensity Factor
22. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Pure Semiconductors: Conductivity vs. T
Metallization
Large Hardness
Brittle Fracture
23. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Fourier's Law
Superconductivity
HB (Brinell Hardness)
Why fracture surfaces have faceted texture
24. Becomes harder (more strain) to stretch (elongate)
Thermal Expansion: Symmetric curve
Two ways to measure heat capacity
Work Hardening
Reflectance of Non-Metals
25. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Lithography
Ductile-to-Brittle Transition
Internal magnetic moments
Where does DBTT occur?
26. Specific heat = energy input/(mass*temperature change)
Impact - Toughness
HB (Brinell Hardness)
Specific Heat
Translucent
27. 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
Fourier's Law
Superconductivity
Opacifiers
Thermal Conductivity
28. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Domains in Ferromagnetic & Ferrimagnetic Materials
Stress Intensity values
Linewidth
Metallization
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
Hysteresis and Permanent Magnetization
Generation of a Magnetic Field - Vacuum
Specific Heat
Holloman Equation
30. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Dependence of Heat Capacity on Temperature
Opacifiers
Response to a Magnetic Field
Two kinds of Reflection
31. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Fatigue
Ductile Materials
Domains in Ferromagnetic & Ferrimagnetic Materials
Two ways to measure heat capacity
32. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Plastic Deformation (Metals)
Metals: Resistivity vs. T - Impurities
True Stress
Internal magnetic moments
33. 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
Thermal expansion
Stress Intensity Factor
Not severe
Internal magnetic moments
34. 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.
Brittle Ceramics
Superconductivity
M is known as what?
Reflectance of Non-Metals
35. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Ductile Fracture
Stages of Failure: Ductile Fracture
Refraction
Extrinsic Semiconductors
36. There is always some statistical distribution of flaws or defects.
Soft Magnetic Materials
Force Decomposition
Yield and Reliability
There is no perfect material?
37. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Magnetic Storage
Energy States: Insulators and Semiconductors
How to gage the extent of plastic deformation
Stress Intensity Factor
38. Different orientation of cleavage planes in grains.
Force Decomposition
Fatigue
Why fracture surfaces have faceted texture
Griffith Crack Model
39. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Extrinsic Semiconductors
Ductile-to-Brittle Transition
LASER
Engineering Fracture Performance
40. ...occurs in bcc metals but not in fcc metals.
Where does DBTT occur?
What do magnetic moments arise from?
Intrinsic Semiconductors
Luminescence
41. 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.
Diamagnetic Materials
Brittle Ceramics
Linewidth
Heat Capacity
42. Cracks propagate along grain boundaries.
Intergranular Fracture
Refraction
Hysteresis and Permanent Magnetization
Bending tests
43. 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.
Brittle Ceramics
Heat Capacity from an Atomic Prospective
Linewidth
Thermal expansion
44. Elastic means reversible! This is not a permanent deformation.
Elastic Deformation
Influence of Temperature on Magnetic Behavior
Heat Capacity from an Atomic Prospective
Hysteresis and Permanent Magnetization
45. 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
Why materials fail in service
What do magnetic moments arise from?
Oxidation
Where does DBTT occur?
46. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
Thermal Stresses
Ductile-to-Brittle Transition
Two kinds of Reflection
Pure Semiconductors: Conductivity vs. T
47. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Plastic Deformation (Metals)
How an LCD works
Film Deposition
HB (Brinell Hardness)
48. Another optical property - Depends on the wavelength of the visible spectrum.
Color
Specific Heat
Metallization
Bending tests
49. Metals are good conductors since their _______is only partially filled.
Intrinsic Semiconductors
Valence band
Thermal expansion
Energy States: Insulators and Semiconductors
50. These materials are relatively unaffected by magnetic fields.
Diamagnetic Materials
Why do ceramics have larger bonding energy?
How an LCD works
Meissner Effect