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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. 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
Reflection of Light for Metals
Transgranular Fracture
Generation of a Magnetic Field - Within a Solid Material
Yield and Reliability
2. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
High impact energy
Bending tests
Soft Magnetic Materials
Metallization
3. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Thermal Stresses
Soft Magnetic Materials
Diamagnetic Materials
Opacity
4. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Refraction
Holloman Equation
Dependence of Heat Capacity on Temperature
Why fracture surfaces have faceted texture
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
Brittle Fracture
Oxidation
How to gage the extent of plastic deformation
Soft Magnetic Materials
6. 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)
Impact - Toughness
To improve fatigue life
Thermal Stresses
Generation of a Magnetic Field - Vacuum
7. 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
Thermal Conductivity
Thermal Expansion: Symmetric curve
Scattering
8. Emitted light is in phase
Coherent
Hysteresis and Permanent Magnetization
Generation of a Magnetic Field - Within a Solid Material
Soft Magnetic Materials
9. 1. Tc= critical temperature- if T>Tc not superconducting 2. Jc= critical current density - if J>Jc not superconducting 3. Hc= critical magnetic field - if H > Hc not superconducting
Brittle Ceramics
Hardness
Critical Properties of Superconductive Materials
Thermal Stresses
10. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Opaque
Refraction
Holloman Equation
Relative Permeability
11. 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
Coherent
Incoherent
Refraction
Liquid Crystal Displays (LCD's)
12. Increase temperature - no increase in interatomic separation - no thermal expansion
Thermal Expansion: Symmetric curve
Scattering
Soft Magnetic Materials
Incident Light
13. 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.
There is no perfect material?
Metallization
M is known as what?
Shear and Tensile Stress
14. 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.
The three modes of crack surface displacement
Brittle Fracture
Metals: Resistivity vs. T - Impurities
Luminescence examples
15. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
What do magnetic moments arise from?
Where does DBTT occur?
Soft Magnetic Materials
Transparent
16. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
True Strain
Generation of a Magnetic Field - Within a Solid Material
Response to a Magnetic Field
Rockwell
17. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Thermal Expansion: Symmetric curve
Influence of Temperature on Magnetic Behavior
Impact - Toughness
Brittle Fracture
18. Light Amplification by Stimulated Emission of Radiation
LASER
Why do ceramics have larger bonding energy?
Impact - Toughness
True Stress
19. They are used to assess properties of ceramics & glasses.
Oxidation
Coherent
Bending tests
Soft Magnetic Materials
20. 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.
True Strain
Translucent
Iron-Silicon Alloy in Transformer Cores
Scattering
21. The ability of a material to be rapidly cooled and not fracture
Thermal Shock Resistance
Two ways to measure heat capacity
Ductile Materials
Plastic Deformation (Metals)
22. Because of ionic & covalent-type bonding.
Why do ceramics have larger bonding energy?
Fatigue
Coefficient of Thermal Expansion
True Strain
23. 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.
Thermal Expansion: Symmetric curve
Brittle Ceramics
Reflectance of Non-Metals
Extrinsic Semiconductors
24. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Color
True Stress
Sparkle of Diamonds
Critical Properties of Superconductive Materials
25. The size of the material changes with a change in temperature - polymers have the largest values
Iron-Silicon Alloy in Transformer Cores
Coefficient of Thermal Expansion
Holloman Equation
Valence band
26. Undergo little or no plastic deformation.
How to gage the extent of plastic deformation
Brittle Materials
Shear and Tensile Stress
Bending tests
27. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Sparkle of Diamonds
Two kinds of Reflection
Domains in Ferromagnetic & Ferrimagnetic Materials
Fatigue
28. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Paramagnetic Materials
Why materials fail in service
Two ways to measure heat capacity
Reflection of Light for Metals
29. 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
Thermal Shock Resistance
Thermal Stresses
Coefficient of Thermal Expansion
Reflection of Light for Metals
30. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION
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31. A high index of refraction (n value) allows for multiple internal reactions.
Opacifiers
Sparkle of Diamonds
Intergranular Fracture
Iron-Silicon Alloy in Transformer Cores
32. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Valence band
Stress Intensity values
What do magnetic moments arise from?
Stages of Failure: Ductile Fracture
33. For a metal - there is no ______ - only reflection
Hysteresis and Permanent Magnetization
Opacity
Refraction
Electromigration
34. Process by which metal atoms diffuse because of a potential.
Brittle Ceramics
Intrinsic Semiconductors
Electromigration
Holloman Equation
35. 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
Why do ceramics have larger bonding energy?
Opacity
True Stress
Impact - Toughness
36. # of thermally generated electrons = # of holes (broken bonds)
High impact energy
Incident Light
What do magnetic moments arise from?
Intrinsic Semiconductors
37. 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
High impact energy
The Transistor
Lithography
Where does DBTT occur?
38. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
The three modes of crack surface displacement
4 Types of Magnetism
Reflection of Light for Metals
Incident Light
39. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Hysteresis and Permanent Magnetization
Heat Capacity from an Atomic Prospective
How an LCD works
Scattering
40. 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
Stress Intensity Factor
Incoherent
Brittle Materials
Thermal Shock Resistance
41. 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
Force Decomposition
4 Types of Magnetism
Incoherent
Bending tests
42. 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
Ductile Fracture
Work Hardening
Slip Bands
43. Diffuse image
Translucent
Stress Intensity Factor
Opaque
Ductile Fracture
44. Second phase particles with n > glass.
Energy States: Insulators and Semiconductors
Extrinsic Semiconductors
Opacifiers
Luminescence examples
45. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Ductile Fracture
Pure Semiconductors: Conductivity vs. T
The Transistor
Valence band
46. 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
Magnetic Storage
Ductile-to-Brittle Transition
Sparkle of Diamonds
Linewidth
47. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Hard Magnetic Materials
There is no perfect material?
Coherent
Modulus of Rupture (MOR)
48. 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
The three modes of crack surface displacement
Hysteresis and Permanent Magnetization
Iron-Silicon Alloy in Transformer Cores
How an LCD works
49. These materials are "attracted" to magnetic fields.
Brittle Materials
Thermal Expansion: Symmetric curve
Paramagnetic Materials
Rockwell
50. Increase temperature - increase in interatomic separation - thermal expansion
Diamagnetic Materials
Thermal Expansion: Asymmetric curve
Hardness
Generation of a Magnetic Field - Vacuum