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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. 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
Color
Internal magnetic moments
Elastic Deformation
2. Process by which metal atoms diffuse because of a potential.
Stages of Failure: Ductile Fracture
True Stress
Electromigration
The Transistor
3. Growth of an oxide layer by the reaction of oxygen with the substrate - Provides dopant masking and device isolation - IC technology uses 1. Thermal grown oxidation (dry) 2. Wet Oxidation 3. Selective Oxidation
Two kinds of Reflection
Oxidation
True Strain
Why materials fail in service
4. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Force Decomposition
Ductile-to-Brittle Transition
Stress Intensity values
Thermal Stresses
5. Because of ionic & covalent-type bonding.
Critical Properties of Superconductive Materials
How an LCD works
Stages of Failure: Ductile Fracture
Why do ceramics have larger bonding energy?
6. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Hysteresis and Permanent Magnetization
Brittle Fracture
IC Devices: P-N Rectifying Junction
Why do ceramics have larger bonding energy?
7. Different orientation of cleavage planes in grains.
Rockwell
Why do ceramics have larger bonding energy?
Why fracture surfaces have faceted texture
Work Hardening
8. 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.
Elastic Deformation
Etching
Heat Capacity
Transgranular Fracture
9. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
Sparkle of Diamonds
Intergranular Fracture
Diamagnetic Materials
To improve fatigue life
10. Becomes harder (more strain) to stretch (elongate)
Work Hardening
Two ways to measure heat capacity
Why fracture surfaces have faceted texture
How an LCD works
11. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Metallization
M is known as what?
Shear and Tensile Stress
Engineering Fracture Performance
12. 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.
Thermal Conductivity
Relative Permeability
Generation of a Magnetic Field - Vacuum
Reflectance of Non-Metals
13. 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
Liquid Crystal Displays (LCD's)
Brittle Materials
Thermal Conductivity
Critical Properties of Superconductive Materials
14. Undergo little or no plastic deformation.
Brittle Materials
Holloman Equation
Modulus of Rupture (MOR)
Diamagnetic Materials
15. If a material has ________ - then the field generated by those moments must be added to the induced field.
Impact energy
Etching
Internal magnetic moments
Heat Capacity
16. Materials change size when temperature is changed
Coefficient of Thermal Expansion
Two ways to measure heat capacity
Thermal expansion
Hard Magnetic Materials
17. 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.
Film Deposition
Electrical Conduction
Transgranular Fracture
M is known as what?
18. 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.
Shear and Tensile Stress
Plastic Deformation (Metals)
Thermal Shock Resistance
Oxidation
19. These materials are relatively unaffected by magnetic fields.
Diamagnetic Materials
HB (Brinell Hardness)
Thermal expansion
Stress Intensity Factor
20. 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.
HB (Brinell Hardness)
Impact - Toughness
Impact energy
Brittle Ceramics
21. Occur when lots of dislocations move.
Translucent
What do magnetic moments arise from?
Slip Bands
Luminescence examples
22. There is always some statistical distribution of flaws or defects.
There is no perfect material?
Intrinsic Semiconductors
Reflection of Light for Metals
Generation of a Magnetic Field - Vacuum
23. 1. Tensile (opening) 2. Sliding 3. Tearing
Incident Light
Thermal expansion
The three modes of crack surface displacement
Luminescence
24. 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.
Incident Light
Intergranular Fracture
Critical Properties of Superconductive Materials
Scattering
25. 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 Materials
Influence of Temperature on Magnetic Behavior
How to gage the extent of plastic deformation
Thermal Shock Resistance
26. Specific heat = energy input/(mass*temperature change)
Color
Thermal Shock Resistance
The Transistor
Specific Heat
27. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Elastic Deformation
Engineering Fracture Performance
Thermal Expansion: Symmetric curve
Stages of Failure: Ductile Fracture
28. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Not severe
Paramagnetic Materials
Reflectance of Non-Metals
Dependence of Heat Capacity on Temperature
29. 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
Valence band
Luminescence examples
Yield and Reliability
30. 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
Brittle Fracture
4 Types of Magnetism
Metals: Resistivity vs. T - Impurities
Incoherent
31. Second phase particles with n > glass.
To improve fatigue life
Color
Opacifiers
Why do ceramics have larger bonding energy?
32. 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
High impact energy
To improve fatigue life
Meissner Effect
33. - 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
Luminescence
What do magnetic moments arise from?
4 Types of Magnetism
Charpy or Izod test
34. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
LASER
Sparkle of Diamonds
Impact - Toughness
Engineering Fracture Performance
35. A high index of refraction (n value) allows for multiple internal reactions.
Sparkle of Diamonds
Incident Light
Thermal Stresses
Intrinsic Semiconductors
36. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Incident Light
Luminescence
Why fracture surfaces have faceted texture
Modulus of Rupture (MOR)
37. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Why fracture surfaces have faceted texture
4 Types of Magnetism
Hardness
Modulus of Rupture (MOR)
38. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
What do magnetic moments arise from?
Ductile-to-Brittle Transition
M is known as what?
Why materials fail in service
39. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
True Strain
HB (Brinell Hardness)
Coherent
Hardness
40. Sigma=ln(li/lo)
HB (Brinell Hardness)
True Strain
Extrinsic Semiconductors
Reflectance of Non-Metals
41. Width of smallest feature obtainable on Si surface
Electromigration
Linewidth
Thermal expansion
Griffith Crack Model
42. Another optical property - Depends on the wavelength of the visible spectrum.
Force Decomposition
Color
Coefficient of Thermal Expansion
Modulus of Rupture (MOR)
43. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Fourier's Law
Luminescence
Magnetic Storage
Incoherent
44. Increase temperature - no increase in interatomic separation - no thermal expansion
Thermal Expansion: Symmetric curve
Luminescence examples
Brittle Ceramics
Heat Capacity from an Atomic Prospective
45. 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
The three modes of crack surface displacement
Yield and Reliability
Brittle Fracture
Opacity
46. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Stages of Failure: Ductile Fracture
Pure Semiconductors: Conductivity vs. T
Superconductivity
How an LCD works
47. Resistance to plastic deformation of cracking in compression - and better wear properties.
Stress Intensity values
Large Hardness
Modulus of Rupture (MOR)
Elastic Deformation
48. Cracks propagate along grain boundaries.
Intergranular Fracture
Dependence of Heat Capacity on Temperature
Intrinsic Semiconductors
Heat Capacity from an Atomic Prospective
49. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Two kinds of Reflection
Coefficient of Thermal Expansion
The three modes of crack surface displacement
Heat Capacity from an Atomic Prospective
50. High toughness; material resists crack propagation.
Charpy or Izod test
The Transistor
High impact energy
Etching