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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. 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)
Elastic Deformation
Ductile Materials
Rockwell
Sparkle of Diamonds
2. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Not severe
Thermal Expansion: Asymmetric curve
Stages of Failure: Ductile Fracture
HB (Brinell Hardness)
3. 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.
Coefficient of Thermal Expansion
Impact - Toughness
Magnetic Storage Media Types
Heat Capacity
4. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
Pure Semiconductors: Conductivity vs. T
Thermal Expansion: Asymmetric curve
Etching
Opaque
5. 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
Yield and Reliability
Hysteresis and Permanent Magnetization
Ductile Materials
Charpy or Izod test
6. Increase temperature - increase in interatomic separation - thermal expansion
Intrinsic Semiconductors
Thermal Expansion: Asymmetric curve
Transparent
Energy States: Insulators and Semiconductors
7. Wet: isotropic - under cut Dry: ansiotropic - directional
Impact - Toughness
Etching
Thermal Expansion: Asymmetric curve
Magnetic Storage Media Types
8. These materials are relatively unaffected by magnetic fields.
Etching
There is no perfect material?
Reflectance of Non-Metals
Diamagnetic Materials
9. 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.
Thermal expansion
Intrinsic Semiconductors
Scattering
Metallization
10. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Magnetic Storage Media Types
Generation of a Magnetic Field - Within a Solid Material
HB (Brinell Hardness)
To improve fatigue life
11. 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.
Opaque
Relative Permeability
Impact - Toughness
Electrical Conduction
12. The size of the material changes with a change in temperature - polymers have the largest values
Coefficient of Thermal Expansion
Hysteresis and Permanent Magnetization
Intergranular Fracture
Lithography
13. 1. Necking 2. Cavity formation 3. Cavity coalescence to form cracks 4. Crack propagation (growth) 5. Fracture
Fourier's Law
Thermal Conductivity
Why materials fail in service
Stages of Failure: Ductile Fracture
14. Small Coercivities - Used for electric motors - Example: commercial iron 99.95 Fe
Soft Magnetic Materials
Metallization
Influence of Temperature on Magnetic Behavior
Color
15. Undergo extensive plastic deformation prior to failure.
Etching
4 Types of Magnetism
Ductile Materials
LASER
16. Diffuse image
Hysteresis and Permanent Magnetization
Diamagnetic Materials
Thermal Expansion: Symmetric curve
Translucent
17. 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
Impact - Toughness
Heat Capacity
How an LCD works
Thermal Conductivity
18. 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
Coefficient of Thermal Expansion
Transgranular Fracture
Engineering Fracture Performance
Refraction
19. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Conduction & Electron Transport
Superconductivity
Heat Capacity from an Atomic Prospective
Impact - Toughness
20. Second phase particles with n > glass.
Stages of Failure: Ductile Fracture
Opacifiers
Two kinds of Reflection
How to gage the extent of plastic deformation
21. Process by which metal atoms diffuse because of a potential.
The Transistor
Rockwell
Electromigration
Energy States: Insulators and Semiconductors
22. Ability to transmit a clear image - The image is clear.
Modulus of Rupture (MOR)
Pure Semiconductors: Conductivity vs. T
Transparent
Electromigration
23. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Thermal Stresses
Intrinsic Semiconductors
Dependence of Heat Capacity on Temperature
Internal magnetic moments
24. 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
Color
Iron-Silicon Alloy in Transformer Cores
Lithography
Incident Light
25. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Why fracture surfaces have faceted texture
Luminescence
Iron-Silicon Alloy in Transformer Cores
Extrinsic Semiconductors
26. Ohms Law: voltage drop = current * resistance
Electrical Conduction
Fatigue
Thermal Stresses
Transgranular Fracture
27. 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.
Brittle Ceramics
Opacity
Reflectance of Non-Metals
Hardness
28. 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.
Relative Permeability
Hardness
Luminescence
Reflection of Light for Metals
29. Without passing a current a continually varying magnetic field will cause a current to flow
Why fracture surfaces have faceted texture
Film Deposition
Brittle Ceramics
Response to a Magnetic Field
30. Cracks pass through grains - often along specific crystal planes.
Transgranular Fracture
Brittle Materials
HB (Brinell Hardness)
Opacifiers
31. 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."
Ductile Materials
Superconductivity
There is no perfect material?
Charpy or Izod test
32. # of thermally generated electrons = # of holes (broken bonds)
Intrinsic Semiconductors
Force Decomposition
Sparkle of Diamonds
Holloman Equation
33. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Specific Heat
Influence of Temperature on Magnetic Behavior
Etching
Two kinds of Reflection
34. 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
Linewidth
HB (Brinell Hardness)
Rockwell
Critical Properties of Superconductive Materials
35. Cracks propagate along grain boundaries.
Film Deposition
Coefficient of Thermal Expansion
Intergranular Fracture
Rockwell
36. 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
Griffith Crack Model
Lithography
Metallization
37. High toughness; material resists crack propagation.
Reflection of Light for Metals
Bending tests
High impact energy
Plastic Deformation (Metals)
38. 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.
Meissner Effect
M is known as what?
Metals: Resistivity vs. T - Impurities
Why do ceramics have larger bonding energy?
39. Emitted light is in phase
Bending tests
Coherent
Plastic Deformation (Metals)
Shear and Tensile Stress
40. - 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
Film Deposition
Luminescence
What do magnetic moments arise from?
Pure Semiconductors: Conductivity vs. T
41. Resistance to plastic deformation of cracking in compression - and better wear properties.
Large Hardness
Elastic Deformation
Diamagnetic Materials
Coefficient of Thermal Expansion
42. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Internal magnetic moments
Lithography
Transgranular Fracture
M is known as what?
43. Occur when lots of dislocations move.
Slip Bands
Impact - Toughness
What do magnetic moments arise from?
Yield and Reliability
44. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
Stages of Failure: Ductile Fracture
Diamagnetic Materials
Elastic Deformation
Fatigue
45. Elastic means reversible! This is not a permanent deformation.
Elastic Deformation
Meissner Effect
Opacifiers
Yield and Reliability
46. If a material has ________ - then the field generated by those moments must be added to the induced field.
Engineering Fracture Performance
Electrical Conduction
Internal magnetic moments
Holloman Equation
47. 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
Oxidation
Stages of Failure: Ductile Fracture
Ductile-to-Brittle Transition
Insulators
48. 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
IC Devices: P-N Rectifying Junction
Thermal Stresses
How to gage the extent of plastic deformation
Reflection of Light for Metals
49. ...occurs in bcc metals but not in fcc metals.
Where does DBTT occur?
Slip Bands
Dependence of Heat Capacity on Temperature
Impact energy
50. Created by current through a coil N= total number of turns L= length of turns (m) I= current (ampere) H= applied magnetic field (ampere-turns/m) Bo= magnetic flux density in a vacuum (tesla)
High impact energy
HB (Brinell Hardness)
Generation of a Magnetic Field - Vacuum
Fatigue