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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. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Incident Light
Force Decomposition
Luminescence
Etching
2. 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
Brittle Fracture
Thermal Conductivity
Two kinds of Reflection
3. A high index of refraction (n value) allows for multiple internal reactions.
Sparkle of Diamonds
Lithography
Not severe
Response to a Magnetic Field
4. Ohms Law: voltage drop = current * resistance
Metallization
Electrical Conduction
Translucent
Opacifiers
5. The size of the material changes with a change in temperature - polymers have the largest values
Coefficient of Thermal Expansion
LASER
Linewidth
Slip Bands
6. 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
Why do ceramics have larger bonding energy?
The Transistor
The three modes of crack surface displacement
Electromigration
7. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Ductile Materials
High impact energy
Hard Magnetic Materials
What do magnetic moments arise from?
8. 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
Where does DBTT occur?
Ductile Materials
True Stress
9. They are used to assess properties of ceramics & glasses.
Soft Magnetic Materials
Why do ceramics have larger bonding energy?
Bending tests
What do magnetic moments arise from?
10. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Two kinds of Reflection
Energy States: Insulators and Semiconductors
Relative Permeability
Ductile Fracture
11. Width of smallest feature obtainable on Si surface
Stages of Failure: Ductile Fracture
Linewidth
Force Decomposition
Rockwell
12. 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
Two kinds of Reflection
Large Hardness
Critical Properties of Superconductive Materials
Hysteresis and Permanent Magnetization
13. 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
Shear and Tensile Stress
Yield and Reliability
Linewidth
Translucent
14. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Valence band
Incoherent
Conduction & Electron Transport
Rockwell
15. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
Shear and Tensile Stress
Stress Intensity Factor
Meissner Effect
Iron-Silicon Alloy in Transformer Cores
16. Another optical property - Depends on the wavelength of the visible spectrum.
Color
Sparkle of Diamonds
Holloman Equation
Heat Capacity
17. These materials are "attracted" to magnetic fields.
Shear and Tensile Stress
Thermal Stresses
Paramagnetic Materials
Magnetic Storage Media Types
18. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Thermal Expansion: Asymmetric curve
Dependence of Heat Capacity on Temperature
Plastic Deformation (Metals)
Metals: Resistivity vs. T - Impurities
19. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Diamagnetic Materials
Superconductivity
Stress Intensity values
Oxidation
20. 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.
Electrical Conduction
Luminescence examples
Heat Capacity
Force Decomposition
21. 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
Influence of Temperature on Magnetic Behavior
Oxidation
Response to a Magnetic Field
There is no perfect material?
22. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Stages of Failure: Ductile Fracture
Incoherent
Soft Magnetic Materials
Reflectance of Non-Metals
23. 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
Impact energy
Fatigue
Thermal Stresses
24. 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.
Intrinsic Semiconductors
Transparent
Critical Properties of Superconductive Materials
Shear and Tensile Stress
25. The ability of a material to be rapidly cooled and not fracture
Metals: Resistivity vs. T - Impurities
Thermal Shock Resistance
Generation of a Magnetic Field - Within a Solid Material
M is known as what?
26. Different orientation of cleavage planes in grains.
Why fracture surfaces have faceted texture
Valence band
Color
Stress Intensity values
27. Metals are good conductors since their _______is only partially filled.
Charpy or Izod test
Valence band
Magnetic Storage Media Types
Holloman Equation
28. Resistance to plastic deformation of cracking in compression - and better wear properties.
Two kinds of Reflection
Valence band
Large Hardness
Work Hardening
29. Typical loading conditions are _____ enough to break all inter-atomic bonds
Bending tests
Opacifiers
Not severe
Coefficient of Thermal Expansion
30. Elastic means reversible! This is not a permanent deformation.
Thermal Expansion: Asymmetric curve
Elastic Deformation
Impact energy
True Stress
31. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Two ways to measure heat capacity
How an LCD works
Impact energy
Conduction & Electron Transport
32. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Hysteresis and Permanent Magnetization
Magnetic Storage Media Types
Two kinds of Reflection
Thermal Shock Resistance
33. 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
Bending tests
Engineering Fracture Performance
Coefficient of Thermal Expansion
How an LCD works
34. Wet: isotropic - under cut Dry: ansiotropic - directional
Etching
Hysteresis and Permanent Magnetization
Bending tests
To improve fatigue life
35. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Response to a Magnetic Field
Transparent
Stress Intensity Factor
Thermal Stresses
36. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Metallization
Diamagnetic Materials
Scattering
To improve fatigue life
37. Undergo little or no plastic deformation.
Coherent
Brittle Materials
Stress Intensity values
HB (Brinell Hardness)
38. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Work Hardening
True Stress
Etching
Metals: Resistivity vs. T - Impurities
39. 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.
M is known as what?
Thermal Expansion: Asymmetric curve
Hysteresis and Permanent Magnetization
4 Types of Magnetism
40. 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.
Luminescence examples
Where does DBTT occur?
Metals: Resistivity vs. T - Impurities
Plastic Deformation (Metals)
41. These materials are relatively unaffected by magnetic fields.
Luminescence
Linewidth
Diamagnetic Materials
Charpy or Izod test
42. Diffuse image
Translucent
High impact energy
There is no perfect material?
Lithography
43. 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
Impact energy
4 Types of Magnetism
Brittle Fracture
Why materials fail in service
44. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Brittle Fracture
Generation of a Magnetic Field - Within a Solid Material
Large Hardness
Meissner Effect
45. 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
Impact - Toughness
Conduction & Electron Transport
Refraction
Slip Bands
46. 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.
Coherent
Luminescence examples
Fatigue
Domains in Ferromagnetic & Ferrimagnetic Materials
47. Because of ionic & covalent-type bonding.
Large Hardness
True Stress
Why do ceramics have larger bonding energy?
Thermal Expansion: Symmetric curve
48. Sigma=ln(li/lo)
To improve fatigue life
Thermal expansion
Film Deposition
True Strain
49. Without passing a current a continually varying magnetic field will cause a current to flow
Stress Intensity Factor
HB (Brinell Hardness)
Ductile Materials
Response to a Magnetic Field
50. Stress concentration at a crack tips
Griffith Crack Model
Why materials fail in service
Where does DBTT occur?
Hard Magnetic Materials