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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. High toughness; material resists crack propagation.
Coherent
High impact energy
Influence of Temperature on Magnetic Behavior
Coefficient of Thermal Expansion
2. 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
Intrinsic Semiconductors
What do magnetic moments arise from?
Magnetic Storage
True Strain
3. Without passing a current a continually varying magnetic field will cause a current to flow
True Strain
Response to a Magnetic Field
Why materials fail in service
Thermal Stresses
4. Increase temperature - increase in interatomic separation - thermal expansion
Hysteresis and Permanent Magnetization
Luminescence examples
Rockwell
Thermal Expansion: Asymmetric curve
5. Width of smallest feature obtainable on Si surface
Dependence of Heat Capacity on Temperature
Bending tests
Magnetic Storage Media Types
Linewidth
6. Wet: isotropic - under cut Dry: ansiotropic - directional
Why do ceramics have larger bonding energy?
Opaque
Insulators
Etching
7. Sigma=ln(li/lo)
Holloman Equation
True Strain
Electromigration
Hardness
8. Light Amplification by Stimulated Emission of Radiation
Oxidation
LASER
Sparkle of Diamonds
Rockwell
9. 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.
How to gage the extent of plastic deformation
Brittle Ceramics
Ductile-to-Brittle Transition
To improve fatigue life
10. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Stages of Failure: Ductile Fracture
Meissner Effect
Ductile Fracture
True Stress
11. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Modulus of Rupture (MOR)
Sparkle of Diamonds
Stages of Failure: Ductile Fracture
Generation of a Magnetic Field - Vacuum
12. Ability to transmit a clear image - The image is clear.
IC Devices: P-N Rectifying Junction
Stages of Failure: Ductile Fracture
Transparent
Relative Permeability
13. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Intrinsic Semiconductors
HB (Brinell Hardness)
Impact - Toughness
Sparkle of Diamonds
14. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Metallization
Griffith Crack Model
Liquid Crystal Displays (LCD's)
Hardness
15. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Brittle Fracture
Translucent
Slip Bands
Fatigue
16. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Ductile Fracture
Influence of Temperature on Magnetic Behavior
Internal magnetic moments
Superconductivity
17. 1. Tensile (opening) 2. Sliding 3. Tearing
Generation of a Magnetic Field - Vacuum
The three modes of crack surface displacement
How to gage the extent of plastic deformation
Coherent
18. The size of the material changes with a change in temperature - polymers have the largest values
Liquid Crystal Displays (LCD's)
The three modes of crack surface displacement
Stress Intensity values
Coefficient of Thermal Expansion
19. 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
Thermal expansion
Thermal Conductivity
Two kinds of Reflection
Metals: Resistivity vs. T - Impurities
20. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Not severe
Intergranular Fracture
Superconductivity
Heat Capacity
21. These materials are "attracted" to magnetic fields.
Paramagnetic Materials
Why fracture surfaces have faceted texture
M is known as what?
4 Types of Magnetism
22. Stress concentration at a crack tips
Coherent
Incident Light
Griffith Crack Model
Pure Semiconductors: Conductivity vs. T
23. There is always some statistical distribution of flaws or defects.
Coefficient of Thermal Expansion
Hardness
There is no perfect material?
Meissner Effect
24. 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)
Rockwell
Ductile Materials
Pure Semiconductors: Conductivity vs. T
Ductile Fracture
25. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Dependence of Heat Capacity on Temperature
Transparent
Reflection of Light for Metals
Two ways to measure heat capacity
26. 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
How an LCD works
There is no perfect material?
True Strain
Dependence of Heat Capacity on Temperature
27. 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
Soft Magnetic Materials
Engineering Fracture Performance
Hysteresis and Permanent Magnetization
28. Metals are good conductors since their _______is only partially filled.
Holloman Equation
Metallization
Valence band
Relative Permeability
29. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Opacity
Insulators
Extrinsic Semiconductors
Two kinds of Reflection
30. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Impact - Toughness
LASER
Two ways to measure heat capacity
Slip Bands
31. ...occurs in bcc metals but not in fcc metals.
Generation of a Magnetic Field - Within a Solid Material
Brittle Ceramics
Heat Capacity from an Atomic Prospective
Where does DBTT occur?
32. For a metal - there is no ______ - only reflection
Refraction
Reflection of Light for Metals
4 Types of Magnetism
Slip Bands
33. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Thermal Stresses
4 Types of Magnetism
The Transistor
Slip Bands
34. 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.
Intergranular Fracture
Stress Intensity Factor
Plastic Deformation (Metals)
Sparkle of Diamonds
35. 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
Refraction
The Transistor
High impact energy
Color
36. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Opacity
Griffith Crack Model
To improve fatigue life
IC Devices: P-N Rectifying Junction
37. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Thermal Shock Resistance
Stages of Failure: Ductile Fracture
Energy States: Insulators and Semiconductors
Internal magnetic moments
38. 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
Reflection of Light for Metals
Impact energy
Conduction & Electron Transport
Energy States: Insulators and Semiconductors
39. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Etching
Modulus of Rupture (MOR)
Opaque
Relative Permeability
40. Process by which metal atoms diffuse because of a potential.
Brittle Ceramics
Thermal Expansion: Asymmetric curve
Electromigration
Transparent
41. Specific heat = energy input/(mass*temperature change)
Thermal Expansion: Symmetric curve
Intrinsic Semiconductors
Specific Heat
Meissner Effect
42. 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.
Ductile Materials
Coherent
Insulators
To improve fatigue life
43. Cracks pass through grains - often along specific crystal planes.
Transgranular Fracture
High impact energy
Linewidth
Luminescence
44. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Electrical Conduction
Fourier's Law
Incident Light
Conduction & Electron Transport
45. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Brittle Fracture
HB (Brinell Hardness)
Fatigue
Incident Light
46. Emitted light is in phase
Stress Intensity Factor
Metallization
Coherent
Elastic Deformation
47. 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.
Luminescence
Luminescence examples
Meissner Effect
Hardness
48. 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
Transgranular Fracture
Elastic Deformation
Holloman Equation
49. 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.
Soft Magnetic Materials
M is known as what?
Stress Intensity values
Scattering
50. 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 Ceramics
Generation of a Magnetic Field - Vacuum
Extrinsic Semiconductors
How to gage the extent of plastic deformation