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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. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
The three modes of crack surface displacement
Modulus of Rupture (MOR)
Why fracture surfaces have faceted texture
Electromigration
2. Light Amplification by Stimulated Emission of Radiation
Why do ceramics have larger bonding energy?
Linewidth
Luminescence
LASER
3. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Electrical Conduction
Thermal expansion
Etching
Energy States: Insulators and Semiconductors
4. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Holloman Equation
Thermal Stresses
Liquid Crystal Displays (LCD's)
Generation of a Magnetic Field - Within a Solid Material
5. 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.
Generation of a Magnetic Field - Vacuum
M is known as what?
Brittle Ceramics
Oxidation
6. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Stress Intensity Factor
Lithography
Heat Capacity
Coherent
7. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Why fracture surfaces have faceted texture
Conduction & Electron Transport
To improve fatigue life
Electromigration
8. Loss of image transmission - You get no image - There is no light transmission - and therefore reflects - scatters - or absorbs ALL of it. Both mirrors and carbon black are opaque.
Metallization
Reflection of Light for Metals
Diamagnetic Materials
Opaque
9. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Ductile-to-Brittle Transition
Metallization
Hysteresis and Permanent Magnetization
Film Deposition
10. High toughness; material resists crack propagation.
Hysteresis and Permanent Magnetization
Thermal Stresses
High impact energy
Coherent
11. 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.
4 Types of Magnetism
Critical Properties of Superconductive Materials
Pure Semiconductors: Conductivity vs. T
Reflectance of Non-Metals
12. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Shear and Tensile Stress
Plastic Deformation (Metals)
Ductile Fracture
Influence of Temperature on Magnetic Behavior
13. Width of smallest feature obtainable on Si surface
Thermal expansion
LASER
Thermal Expansion: Symmetric curve
Linewidth
14. 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.
The three modes of crack surface displacement
High impact energy
Plastic Deformation (Metals)
Stress Intensity Factor
15. These materials are "attracted" to magnetic fields.
Specific Heat
LASER
Paramagnetic Materials
Generation of a Magnetic Field - Vacuum
16. Undergo little or no plastic deformation.
Brittle Materials
Work Hardening
Iron-Silicon Alloy in Transformer Cores
True Strain
17. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Film Deposition
Heat Capacity
Conduction & Electron Transport
Etching
18. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Iron-Silicon Alloy in Transformer Cores
There is no perfect material?
Incident Light
Two ways to measure heat capacity
19. There is always some statistical distribution of flaws or defects.
Rockwell
There is no perfect material?
Not severe
Luminescence examples
20. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Ductile Fracture
Charpy or Izod test
The three modes of crack surface displacement
Luminescence
21. 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
There is no perfect material?
Hard Magnetic Materials
Brittle Ceramics
Yield and Reliability
22. 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.
Large Hardness
Electromigration
Shear and Tensile Stress
Stages of Failure: Ductile Fracture
23. Another optical property - Depends on the wavelength of the visible spectrum.
Holloman Equation
Paramagnetic Materials
Color
Brittle Materials
24. Sigma=ln(li/lo)
Fatigue
Heat Capacity
True Strain
Two kinds of Reflection
25. 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.
IC Devices: P-N Rectifying Junction
Color
LASER
Hardness
26. 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
Hysteresis and Permanent Magnetization
Opacifiers
Magnetic Storage
Coherent
27. Measures impact energy 1. Strike a notched sample with an anvil 2. Measure how far the anvil travels following impact 3. Distance traveled is related to energy required to break the sample 4. Very high rate of loading. Makes materials more "brittle."
Charpy or Izod test
Thermal Expansion: Asymmetric curve
Not severe
Domains in Ferromagnetic & Ferrimagnetic Materials
28. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Why materials fail in service
Extrinsic Semiconductors
Brittle Fracture
Oxidation
29. 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
Stages of Failure: Ductile Fracture
Stress Intensity Factor
Slip Bands
Griffith Crack Model
30. Undergo extensive plastic deformation prior to failure.
Why fracture surfaces have faceted texture
To improve fatigue life
Ductile Materials
Iron-Silicon Alloy in Transformer Cores
31. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Hard Magnetic Materials
Slip Bands
Stress Intensity Factor
Fourier's Law
32. Cracks pass through grains - often along specific crystal planes.
Meissner Effect
Generation of a Magnetic Field - Vacuum
Thermal Expansion: Asymmetric curve
Transgranular Fracture
33. 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
Stages of Failure: Ductile Fracture
How to gage the extent of plastic deformation
Stress Intensity Factor
Valence band
34. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Two kinds of Reflection
To improve fatigue life
Color
Refraction
35. Elastic means reversible! This is not a permanent deformation.
Transparent
What do magnetic moments arise from?
Large Hardness
Elastic Deformation
36. Second phase particles with n > glass.
Ductile Fracture
Opacifiers
Soft Magnetic Materials
Hardness
37. 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 examples
M is known as what?
Stress Intensity values
Stress Intensity Factor
38. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Influence of Temperature on Magnetic Behavior
Thermal Stresses
Griffith Crack Model
Domains in Ferromagnetic & Ferrimagnetic Materials
39. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
What do magnetic moments arise from?
Fatigue
Yield and Reliability
IC Devices: P-N Rectifying Junction
40. ...occurs in bcc metals but not in fcc metals.
Where does DBTT occur?
Electrical Conduction
The Transistor
Luminescence
41. Increase temperature - increase in interatomic separation - thermal expansion
Two ways to measure heat capacity
Thermal Expansion: Asymmetric curve
The Transistor
Pure Semiconductors: Conductivity vs. T
42. - 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
Metals: Resistivity vs. T - Impurities
Stress Intensity values
Two ways to measure heat capacity
Diamagnetic Materials
43. Ability to transmit a clear image - The image is clear.
Relative Permeability
Luminescence
Transparent
True Stress
44. 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
Refraction
Griffith Crack Model
Iron-Silicon Alloy in Transformer Cores
To improve fatigue life
45. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Griffith Crack Model
Two ways to measure heat capacity
Heat Capacity
Impact - Toughness
46. They are used to assess properties of ceramics & glasses.
Electromigration
Meissner Effect
Bending tests
Valence band
47. 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
Scattering
4 Types of Magnetism
Domains in Ferromagnetic & Ferrimagnetic Materials
48. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Why materials fail in service
Engineering Fracture Performance
Translucent
Generation of a Magnetic Field - Vacuum
49. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Conduction & Electron Transport
Pure Semiconductors: Conductivity vs. T
Magnetic Storage
High impact energy
50. 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
M is known as what?
Energy States: Insulators and Semiconductors
Refraction