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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. Metals are good conductors since their _______is only partially filled.
Valence band
Bending tests
Hysteresis and Permanent Magnetization
How to gage the extent of plastic deformation
2. The size of the material changes with a change in temperature - polymers have the largest values
Metallization
Stages of Failure: Ductile Fracture
Opacity
Coefficient of Thermal Expansion
3. These materials are "attracted" to magnetic fields.
How to gage the extent of plastic deformation
M is known as what?
Paramagnetic Materials
Domains in Ferromagnetic & Ferrimagnetic Materials
4. 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
The Transistor
Electrical Conduction
Thermal Shock Resistance
5. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Pure Semiconductors: Conductivity vs. T
Reflection of Light for Metals
IC Devices: P-N Rectifying Junction
Diamagnetic Materials
6. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Hard Magnetic Materials
Film Deposition
Incident Light
Etching
7. Another optical property - Depends on the wavelength of the visible spectrum.
M is known as what?
Color
Incident Light
Rockwell
8. There is always some statistical distribution of flaws or defects.
Liquid Crystal Displays (LCD's)
Ductile-to-Brittle Transition
Heat Capacity
There is no perfect material?
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
Stress Intensity values
Iron-Silicon Alloy in Transformer Cores
Not severe
Heat Capacity
10. High toughness; material resists crack propagation.
High impact energy
Thermal Expansion: Asymmetric curve
Heat Capacity
Coherent
11. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Heat Capacity from an Atomic Prospective
Thermal Stresses
Yield and Reliability
Plastic Deformation (Metals)
12. 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
Reflection of Light for Metals
Insulators
Two ways to measure heat capacity
13. 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.
True Stress
Where does DBTT occur?
IC Devices: P-N Rectifying Junction
Shear and Tensile Stress
14. 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.
Energy States: Insulators and Semiconductors
Brittle Ceramics
Reflection of Light for Metals
Holloman Equation
15. Light Amplification by Stimulated Emission of Radiation
Magnetic Storage
LASER
Paramagnetic Materials
Impact - Toughness
16. Undergo little or no plastic deformation.
Paramagnetic Materials
Fatigue
Shear and Tensile Stress
Brittle Materials
17. Increase temperature - increase in interatomic separation - thermal expansion
Dependence of Heat Capacity on Temperature
Ductile Fracture
Thermal Expansion: Asymmetric curve
Magnetic Storage Media Types
18. Materials change size when temperature is changed
Rockwell
Film Deposition
Thermal expansion
LASER
19. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION
20. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Thermal Expansion: Symmetric curve
True Strain
Lithography
Transparent
21. Typical loading conditions are _____ enough to break all inter-atomic bonds
True Strain
Not severe
Liquid Crystal Displays (LCD's)
Ductile Fracture
22. These materials are relatively unaffected by magnetic fields.
Transparent
Diamagnetic Materials
Fatigue
Large Hardness
23. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Etching
Film Deposition
Refraction
Brittle Fracture
24. Without passing a current a continually varying magnetic field will cause a current to flow
Incident Light
Response to a Magnetic Field
Domains in Ferromagnetic & Ferrimagnetic Materials
Brittle Ceramics
25. Emitted light is in phase
Insulators
Coherent
Hardness
Two kinds of Reflection
26. Increase temperature - no increase in interatomic separation - no thermal expansion
Translucent
Bending tests
Thermal Expansion: Symmetric curve
Fourier's Law
27. Elastic means reversible! This is not a permanent deformation.
Elastic Deformation
Translucent
Two kinds of Reflection
Impact energy
28. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Soft Magnetic Materials
Intergranular Fracture
Work Hardening
Energy States: Insulators and Semiconductors
29. 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
Superconductivity
Dependence of Heat Capacity on Temperature
There is no perfect material?
Yield and Reliability
30. 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.
Generation of a Magnetic Field - Within a Solid Material
Engineering Fracture Performance
Plastic Deformation (Metals)
Film Deposition
31. 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
Luminescence
Hardness
Iron-Silicon Alloy in Transformer Cores
Charpy or Izod test
32. 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.
Insulators
Intrinsic Semiconductors
True Strain
Superconductivity
33. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
4 Types of Magnetism
Two ways to measure heat capacity
Incoherent
Superconductivity
34. Specific heat = energy input/(mass*temperature change)
Thermal Stresses
Brittle Ceramics
Two kinds of Reflection
Specific Heat
35. ...occurs in bcc metals but not in fcc metals.
Critical Properties of Superconductive Materials
Where does DBTT occur?
Relative Permeability
Energy States: Insulators and Semiconductors
36. 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
True Stress
4 Types of Magnetism
LASER
37. - The emission of light from a substance due to the absorption of energy. (Could be radiation - mechanical - or chemical energy. Could also be energetic particles.) - Traps and activator levels are produced by impurity additions to the material - Whe
Griffith Crack Model
4 Types of Magnetism
Hysteresis and Permanent Magnetization
Luminescence
38. 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.
Reflectance of Non-Metals
Rockwell
Shear and Tensile Stress
Luminescence examples
39. Second phase particles with n > glass.
Opacifiers
Iron-Silicon Alloy in Transformer Cores
Yield and Reliability
Oxidation
40. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Iron-Silicon Alloy in Transformer Cores
Two kinds of Reflection
Dependence of Heat Capacity on Temperature
Electrical Conduction
41. 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
Stages of Failure: Ductile Fracture
Ductile Materials
Critical Properties of Superconductive Materials
Metals: Resistivity vs. T - Impurities
42. 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
Film Deposition
How an LCD works
Insulators
Brittle Fracture
43. 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
Relative Permeability
Stress Intensity Factor
Scattering
Specific Heat
44. A high index of refraction (n value) allows for multiple internal reactions.
Critical Properties of Superconductive Materials
Ductile Materials
Sparkle of Diamonds
Valence band
45. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Impact - Toughness
Extrinsic Semiconductors
Force Decomposition
Thermal Expansion: Symmetric curve
46. They are used to assess properties of ceramics & glasses.
Thermal Expansion: Asymmetric curve
Bending tests
Coefficient of Thermal Expansion
Energy States: Insulators and Semiconductors
47. Ohms Law: voltage drop = current * resistance
Intrinsic Semiconductors
Electrical Conduction
Brittle Fracture
Electromigration
48. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
To improve fatigue life
Color
Elastic Deformation
IC Devices: P-N Rectifying Junction
49. Diffuse image
Translucent
Impact energy
The three modes of crack surface displacement
Dependence of Heat Capacity on Temperature
50. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Ductile Fracture
Critical Properties of Superconductive Materials
True Stress
Intergranular Fracture