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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. Undergo extensive plastic deformation prior to failure.
How an LCD works
Ductile Materials
Why materials fail in service
Insulators
2. There is always some statistical distribution of flaws or defects.
Plastic Deformation (Metals)
Ductile Fracture
Thermal Stresses
There is no perfect material?
3. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Shear and Tensile Stress
Etching
Pure Semiconductors: Conductivity vs. T
Heat Capacity from an Atomic Prospective
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
Incident Light
Color
Superconductivity
Hysteresis and Permanent Magnetization
5. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Two kinds of Reflection
How an LCD works
Hard Magnetic Materials
Fatigue
6. Stress concentration at a crack tips
Insulators
Shear and Tensile Stress
Why do ceramics have larger bonding energy?
Griffith Crack Model
7. # of thermally generated electrons = # of holes (broken bonds)
Thermal Expansion: Asymmetric curve
Intrinsic Semiconductors
Extrinsic Semiconductors
Electrical Conduction
8. 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
Electromigration
Stress Intensity Factor
Plastic Deformation (Metals)
Holloman Equation
9. - Metals that exhibit high ductility - exhibit high toughness. Ceramics are very strong - but have low ductility and low toughness - Polymers are very ductile but are not generally very strong in shear (compared to metals and ceramics). They have low
Plastic Deformation (Metals)
Stress Intensity values
The Transistor
Heat Capacity from an Atomic Prospective
10. Width of smallest feature obtainable on Si surface
Linewidth
Elastic Deformation
Opacifiers
Metals: Resistivity vs. T - Impurities
11. These materials are relatively unaffected by magnetic fields.
Insulators
Diamagnetic Materials
Stress Intensity values
Why materials fail in service
12. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
There is no perfect material?
Extrinsic Semiconductors
Modulus of Rupture (MOR)
Dependence of Heat Capacity on Temperature
13. Occur when lots of dislocations move.
Relative Permeability
Slip Bands
Reflection of Light for Metals
Thermal Conductivity
14. 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
Slip Bands
Refraction
Pure Semiconductors: Conductivity vs. T
Reflectance of Non-Metals
15. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Brittle Ceramics
Two ways to measure heat capacity
Magnetic Storage Media Types
Thermal Shock Resistance
16. Wet: isotropic - under cut Dry: ansiotropic - directional
Lithography
The Transistor
Refraction
Etching
17. Light Amplification by Stimulated Emission of Radiation
Stages of Failure: Ductile Fracture
Generation of a Magnetic Field - Within a Solid Material
Opacifiers
LASER
18. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
HB (Brinell Hardness)
Soft Magnetic Materials
Refraction
Opacifiers
19. Diffuse image
Stress Intensity Factor
Translucent
Sparkle of Diamonds
Oxidation
20. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Energy States: Insulators and Semiconductors
Incoherent
Domains in Ferromagnetic & Ferrimagnetic Materials
Luminescence
21. A measure of the ease with which a B field can be induced inside a material.
Relative Permeability
Oxidation
There is no perfect material?
Soft Magnetic Materials
22. 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 Fracture
Luminescence
Brittle Ceramics
Impact energy
23. Increase temperature - increase in interatomic separation - thermal expansion
Thermal Expansion: Asymmetric curve
Fatigue
Pure Semiconductors: Conductivity vs. T
Magnetic Storage
24. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Film Deposition
True Strain
Paramagnetic Materials
Work Hardening
25. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Magnetic Storage Media Types
LASER
Why do ceramics have larger bonding energy?
Extrinsic Semiconductors
26. 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.
Heat Capacity
Electromigration
The three modes of crack surface displacement
Ductile Materials
27. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
IC Devices: P-N Rectifying Junction
Why materials fail in service
Electrical Conduction
Thermal Expansion: Asymmetric curve
28. 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
Work Hardening
M is known as what?
Thermal Expansion: Asymmetric curve
29. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Scattering
Incident Light
Hysteresis and Permanent Magnetization
Internal magnetic moments
30. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Thermal Stresses
Metallization
Impact energy
Dependence of Heat Capacity on Temperature
31. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Influence of Temperature on Magnetic Behavior
Metals: Resistivity vs. T - Impurities
Impact energy
Why materials fail in service
32. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Thermal expansion
To improve fatigue life
Electrical Conduction
Hardness
33. Becomes harder (more strain) to stretch (elongate)
Heat Capacity from an Atomic Prospective
Bending tests
Work Hardening
Diamagnetic Materials
34. Without passing a current a continually varying magnetic field will cause a current to flow
High impact energy
Response to a Magnetic Field
Incident Light
How to gage the extent of plastic deformation
35. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Plastic Deformation (Metals)
Energy States: Insulators and Semiconductors
Translucent
Superconductivity
36. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Brittle Fracture
Shear and Tensile Stress
Transparent
Engineering Fracture Performance
37. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Transgranular Fracture
There is no perfect material?
Extrinsic Semiconductors
Modulus of Rupture (MOR)
38. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Influence of Temperature on Magnetic Behavior
What do magnetic moments arise from?
Incoherent
Extrinsic Semiconductors
39. Cracks propagate along grain boundaries.
Intergranular Fracture
Domains in Ferromagnetic & Ferrimagnetic Materials
Large Hardness
Color
40. Is analogous to toughness.
How to gage the extent of plastic deformation
Stress Intensity Factor
Impact energy
Electromigration
41. 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
The Transistor
IC Devices: P-N Rectifying Junction
Incoherent
Impact energy
42. 1. Metals: Thermal energy puts many electrons into a higher energy state. 2. Energy States: Nearby energy states are accessible by thermal fluctuations.
Incident Light
4 Types of Magnetism
Conduction & Electron Transport
Translucent
43. ...occurs in bcc metals but not in fcc metals.
The Transistor
Why do ceramics have larger bonding energy?
Electrical Conduction
Where does DBTT occur?
44. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Thermal Conductivity
Thermal Stresses
Griffith Crack Model
Why materials fail in service
45. For a metal - there is no ______ - only reflection
Incoherent
What do magnetic moments arise from?
Refraction
Magnetic Storage
46. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Insulators
Transgranular Fracture
Metallization
The Transistor
47. 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.
Stress Intensity values
Scattering
Rockwell
Heat Capacity
48. The ability of a material to be rapidly cooled and not fracture
Magnetic Storage Media Types
Soft Magnetic Materials
Thermal Shock Resistance
Not severe
49. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Insulators
Generation of a Magnetic Field - Within a Solid Material
The three modes of crack surface displacement
Holloman Equation
50. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Critical Properties of Superconductive Materials
Opaque
Ductile Fracture
Hardness