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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. 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
Magnetic Storage
True Stress
Electromigration
Paramagnetic Materials
2. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Fourier's Law
Influence of Temperature on Magnetic Behavior
Extrinsic Semiconductors
Plastic Deformation (Metals)
3. 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
Generation of a Magnetic Field - Vacuum
Electrical Conduction
How to gage the extent of plastic deformation
Color
4. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
To improve fatigue life
Insulators
Thermal Stresses
Magnetic Storage Media Types
5. 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.
Transgranular Fracture
Work Hardening
Insulators
Lithography
6. Second phase particles with n > glass.
Diamagnetic Materials
Metallization
Color
Opacifiers
7. 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.
Stress Intensity Factor
Opacity
Reflectance of Non-Metals
Soft Magnetic Materials
8. Specific heat = energy input/(mass*temperature change)
M is known as what?
What do magnetic moments arise from?
Specific Heat
4 Types of Magnetism
9. For a metal - there is no ______ - only reflection
The three modes of crack surface displacement
Refraction
Specific Heat
There is no perfect material?
10. Resistance to plastic deformation of cracking in compression - and better wear properties.
Large Hardness
Extrinsic Semiconductors
Relative Permeability
Thermal Expansion: Symmetric curve
11. 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
Refraction
Response to a Magnetic Field
M is known as what?
Stress Intensity values
12. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Paramagnetic Materials
The three modes of crack surface displacement
Force Decomposition
Heat Capacity from an Atomic Prospective
13. 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.
Conduction & Electron Transport
Thermal Shock Resistance
Engineering Fracture Performance
Luminescence examples
14. The ability of a material to be rapidly cooled and not fracture
Brittle Materials
Electromigration
Thermal Shock Resistance
Etching
15. Metals are good conductors since their _______is only partially filled.
Liquid Crystal Displays (LCD's)
Relative Permeability
Force Decomposition
Valence band
16. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Generation of a Magnetic Field - Within a Solid Material
Why do ceramics have larger bonding energy?
Reflection of Light for Metals
Heat Capacity from an Atomic Prospective
17. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Metallization
To improve fatigue life
M is known as what?
Specific Heat
18. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Superconductivity
Iron-Silicon Alloy in Transformer Cores
Force Decomposition
Valence band
19. 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
Thermal Stresses
Yield and Reliability
Why fracture surfaces have faceted texture
Luminescence examples
20. 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
There is no perfect material?
Ductile Fracture
Force Decomposition
21. - 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
The Transistor
Griffith Crack Model
Pure Semiconductors: Conductivity vs. T
Luminescence
22. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Holloman Equation
Coefficient of Thermal Expansion
Hardness
Lithography
23. Increase temperature - no increase in interatomic separation - no thermal expansion
Color
Thermal Expansion: Symmetric curve
Extrinsic Semiconductors
Thermal Shock Resistance
24. Degree of opacity depends on size and number of particles - Opacity of metals is the result of conduction electrons absorbing photons in the visible range.
Opacity
Transgranular Fracture
Refraction
Metals: Resistivity vs. T - Impurities
25. Stress concentration at a crack tips
Griffith Crack Model
Relative Permeability
LASER
Meissner Effect
26. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Translucent
Thermal expansion
Opaque
IC Devices: P-N Rectifying Junction
27. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
Opacifiers
Intrinsic Semiconductors
True Stress
Iron-Silicon Alloy in Transformer Cores
28. Materials change size when temperature is changed
Heat Capacity from an Atomic Prospective
Incident Light
Thermal Stresses
Thermal expansion
29. 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
Thermal Shock Resistance
LASER
IC Devices: P-N Rectifying Junction
The Transistor
30. 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.
Soft Magnetic Materials
Specific Heat
Hardness
Two kinds of Reflection
31. They are used to assess properties of ceramics & glasses.
Two kinds of Reflection
Slip Bands
Translucent
Bending tests
32. Width of smallest feature obtainable on Si surface
Why do ceramics have larger bonding energy?
HB (Brinell Hardness)
Linewidth
Generation of a Magnetic Field - Within a Solid Material
33. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Incident Light
Rockwell
Luminescence examples
Yield and Reliability
34. These materials are "attracted" to magnetic fields.
Rockwell
Paramagnetic Materials
Work Hardening
The Transistor
35. 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.
Ductile Materials
Scattering
Luminescence
Thermal Shock Resistance
36. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Insulators
Dependence of Heat Capacity on Temperature
Modulus of Rupture (MOR)
Luminescence
37. Is analogous to toughness.
Work Hardening
Engineering Fracture Performance
Electromigration
Impact energy
38. If a material has ________ - then the field generated by those moments must be added to the induced field.
Linewidth
Internal magnetic moments
What do magnetic moments arise from?
Heat Capacity
39. 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.
Hardness
Refraction
Shear and Tensile Stress
Transparent
40. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Elastic Deformation
Electromigration
Stages of Failure: Ductile Fracture
Oxidation
41. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Metals: Resistivity vs. T - Impurities
Hard Magnetic Materials
Engineering Fracture Performance
Thermal Expansion: Asymmetric curve
42. High toughness; material resists crack propagation.
IC Devices: P-N Rectifying Junction
High impact energy
Brittle Materials
Refraction
43. Occur when lots of dislocations move.
Slip Bands
Hard Magnetic Materials
Relative Permeability
Conduction & Electron Transport
44. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Soft Magnetic Materials
Paramagnetic Materials
Impact - Toughness
True Stress
45. These materials are relatively unaffected by magnetic fields.
Diamagnetic Materials
Domains in Ferromagnetic & Ferrimagnetic Materials
Opaque
Work Hardening
46. 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
IC Devices: P-N Rectifying Junction
The Transistor
Stress Intensity Factor
Intergranular Fracture
47. 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.
Bending tests
Luminescence
IC Devices: P-N Rectifying Junction
Brittle Ceramics
48. Process by which metal atoms diffuse because of a potential.
Lithography
Insulators
Electromigration
Stages of Failure: Ductile Fracture
49. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
What do magnetic moments arise from?
Etching
Valence band
Liquid Crystal Displays (LCD's)
50. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Not severe
Brittle Fracture
HB (Brinell Hardness)
Critical Properties of Superconductive Materials