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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. 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.
Stages of Failure: Ductile Fracture
M is known as what?
Charpy or Izod test
Why materials fail in service
2. Metals are good conductors since their _______is only partially filled.
Luminescence
Valence band
Electrical Conduction
Coefficient of Thermal Expansion
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.
Two ways to measure heat capacity
Critical Properties of Superconductive Materials
Insulators
Energy States: Insulators and Semiconductors
4. 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
Rockwell
Opacifiers
4 Types of Magnetism
Hysteresis and Permanent Magnetization
5. Stress concentration at a crack tips
Reflectance of Non-Metals
Griffith Crack Model
Lithography
Influence of Temperature on Magnetic Behavior
6. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
To improve fatigue life
Two ways to measure heat capacity
Impact - Toughness
Fatigue
7. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Shear and Tensile Stress
Etching
Opacifiers
Incident Light
8. 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
How an LCD works
Impact - Toughness
Specific Heat
Ductile Materials
9. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Thermal Expansion: Symmetric curve
Holloman Equation
True Stress
Thermal Stresses
10. 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.
Thermal Shock Resistance
Ductile-to-Brittle Transition
Heat Capacity
Two kinds of Reflection
11. 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.
Fourier's Law
Scattering
How to gage the extent of plastic deformation
Response to a Magnetic Field
12. Emitted light is in phase
The three modes of crack surface displacement
Coherent
Coefficient of Thermal Expansion
Domains in Ferromagnetic & Ferrimagnetic Materials
13. # of thermally generated electrons = # of holes (broken bonds)
Hysteresis and Permanent Magnetization
True Stress
Magnetic Storage Media Types
Intrinsic Semiconductors
14. Diffuse image
Translucent
Thermal Stresses
Diamagnetic Materials
Magnetic Storage
15. Occur when lots of dislocations move.
Relative Permeability
Meissner Effect
Slip Bands
Thermal Stresses
16. Specific heat = energy input/(mass*temperature change)
Thermal Conductivity
How to gage the extent of plastic deformation
Specific Heat
Electromigration
17. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Two ways to measure heat capacity
Large Hardness
Holloman Equation
Superconductivity
18. Sigma=ln(li/lo)
True Strain
Opacity
Transparent
LASER
19. Different orientation of cleavage planes in grains.
Thermal Stresses
Why fracture surfaces have faceted texture
Oxidation
Iron-Silicon Alloy in Transformer Cores
20. These materials are "attracted" to magnetic fields.
Paramagnetic Materials
Relative Permeability
Thermal Shock Resistance
Plastic Deformation (Metals)
21. Hardness is the resistance of a material to deformation by indentation - Useful in quality control - Hardness can provide a qualitative assessment of strength - Hardness cannot be used to quantitatively infer strength or ductility.
Superconductivity
Hardness
Thermal Conductivity
High impact energy
22. 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
Lithography
Why materials fail in service
Refraction
Ductile Materials
23. 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
Iron-Silicon Alloy in Transformer Cores
Impact energy
Bending tests
High impact energy
24. 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)
Critical Properties of Superconductive Materials
Paramagnetic Materials
Generation of a Magnetic Field - Vacuum
Opaque
25. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
Thermal Stresses
Brittle Materials
Relative Permeability
Meissner Effect
26. 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.
Impact - Toughness
Stress Intensity Factor
Shear and Tensile Stress
Specific Heat
27. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Stress Intensity values
Linewidth
Pure Semiconductors: Conductivity vs. T
Meissner Effect
28. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Dependence of Heat Capacity on Temperature
Hard Magnetic Materials
Reflectance of Non-Metals
Opacity
29. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Transgranular Fracture
Generation of a Magnetic Field - Within a Solid Material
Thermal Shock Resistance
Lithography
30. 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.
Plastic Deformation (Metals)
Reflectance of Non-Metals
Refraction
Two kinds of Reflection
31. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Two kinds of Reflection
Engineering Fracture Performance
The Transistor
Response to a Magnetic Field
32. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Superconductivity
Two kinds of Reflection
To improve fatigue life
Plastic Deformation (Metals)
33. Wet: isotropic - under cut Dry: ansiotropic - directional
Metallization
Work Hardening
Ductile-to-Brittle Transition
Etching
34. 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
Dependence of Heat Capacity on Temperature
Reflectance of Non-Metals
35. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Refraction
Paramagnetic Materials
Modulus of Rupture (MOR)
Domains in Ferromagnetic & Ferrimagnetic Materials
36. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Electromigration
Yield and Reliability
Incoherent
Refraction
37. High toughness; material resists crack propagation.
High impact energy
Liquid Crystal Displays (LCD's)
Why do ceramics have larger bonding energy?
Soft Magnetic Materials
38. Process by which metal atoms diffuse because of a potential.
Electromigration
Ductile Fracture
Extrinsic Semiconductors
M is known as what?
39. Second phase particles with n > glass.
True Strain
Opacity
Opacifiers
Color
40. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Two kinds of Reflection
Why do ceramics have larger bonding energy?
Dependence of Heat Capacity on Temperature
Holloman Equation
41. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
HB (Brinell Hardness)
Charpy or Izod test
Two kinds of Reflection
Stages of Failure: Ductile Fracture
42. Increase temperature - no increase in interatomic separation - no thermal expansion
Metals: Resistivity vs. T - Impurities
Opacity
Thermal Expansion: Symmetric curve
Film Deposition
43. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
How an LCD works
There is no perfect material?
Conduction & Electron Transport
Transgranular Fracture
44. The ability of a material to be rapidly cooled and not fracture
Electrical Conduction
Brittle Materials
Work Hardening
Thermal Shock Resistance
45. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Insulators
Hardness
Relative Permeability
Heat Capacity from an Atomic Prospective
46. Measures Hardness - No major sample damage - Each scales runs to 130 but only useful in range 20-100 - Minor load is 10 kg - Major load: 60 kg (diamond) - 100 kg (1/16 in. ball) - 150 kg (diamond)
True Strain
Rockwell
What do magnetic moments arise from?
Stages of Failure: Ductile Fracture
47. Undergo little or no plastic deformation.
Brittle Materials
Electromigration
Thermal Stresses
HB (Brinell Hardness)
48. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
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49. ...occurs in bcc metals but not in fcc metals.
Thermal Stresses
Brittle Ceramics
Where does DBTT occur?
Ductile Materials
50. Increase temperature - increase in interatomic separation - thermal expansion
Fatigue
Sparkle of Diamonds
Thermal Expansion: Asymmetric curve
Coherent