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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. Undergo little or no plastic deformation.
Diamagnetic Materials
Fourier's Law
Brittle Materials
Engineering Fracture Performance
2. 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
Lithography
Holloman Equation
Hysteresis and Permanent Magnetization
Modulus of Rupture (MOR)
3. 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
Metallization
Coefficient of Thermal Expansion
Reflection of Light for Metals
Slip Bands
4. 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
Extrinsic Semiconductors
Relative Permeability
Iron-Silicon Alloy in Transformer Cores
Electromigration
5. There is always some statistical distribution of flaws or defects.
Two ways to measure heat capacity
What do magnetic moments arise from?
There is no perfect material?
Valence band
6. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION
7. 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
Scattering
Yield and Reliability
Intergranular Fracture
Translucent
8. 1. Ability of the material to absorb energy prior to fracture 2. Short term dynamic stressing - Car collisions - Bullets - Athletic equipment 3. This is different than toughness; energy necessary to push a crack (flaw) through a material 4. Useful in
Impact - Toughness
Impact energy
Thermal Stresses
Conduction & Electron Transport
9. Sigma=ln(li/lo)
To improve fatigue life
True Strain
How an LCD works
How to gage the extent of plastic deformation
10. 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.
Slip Bands
Engineering Fracture Performance
Conduction & Electron Transport
Heat Capacity
11. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Griffith Crack Model
Response to a Magnetic Field
Influence of Temperature on Magnetic Behavior
Superconductivity
12. Another optical property - Depends on the wavelength of the visible spectrum.
Color
Refraction
Refraction
Thermal Expansion: Asymmetric curve
13. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Two kinds of Reflection
LASER
Magnetic Storage
Impact - Toughness
14. 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
Domains in Ferromagnetic & Ferrimagnetic Materials
Intrinsic Semiconductors
Critical Properties of Superconductive Materials
Thermal Conductivity
15. 1. Tensile (opening) 2. Sliding 3. Tearing
Why fracture surfaces have faceted texture
The three modes of crack surface displacement
Ductile-to-Brittle Transition
IC Devices: P-N Rectifying Junction
16. 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.
Hardness
Hysteresis and Permanent Magnetization
Slip Bands
Transgranular Fracture
17. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
LASER
Energy States: Insulators and Semiconductors
Internal magnetic moments
Film Deposition
18. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Coherent
Refraction
Two ways to measure heat capacity
True Stress
19. Materials change size when temperature is changed
To improve fatigue life
Hardness
Coherent
Thermal expansion
20. Because of ionic & covalent-type bonding.
Why do ceramics have larger bonding energy?
Internal magnetic moments
M is known as what?
Brittle Materials
21. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
What do magnetic moments arise from?
Coefficient of Thermal Expansion
Why fracture surfaces have faceted texture
Force Decomposition
22. Emitted light is in phase
Coherent
Brittle Materials
Opaque
Fatigue
23. Failure under cyclic stress 1. It can cause part failure - even though (sigma)max < (sigma)c 2. Causes ~90% of mechanical engineering failures.
True Stress
Fatigue
M is known as what?
Soft Magnetic Materials
24. Energy is stored as atomic vibrations - As temperature increases - the average energy of atomic vibrations increases.
Magnetic Storage
Work Hardening
Heat Capacity from an Atomic Prospective
Brittle Ceramics
25. 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
Critical Properties of Superconductive Materials
Electrical Conduction
The Transistor
Yield and Reliability
26. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Two ways to measure heat capacity
The Transistor
Reflectance of Non-Metals
Influence of Temperature on Magnetic Behavior
27. Process by which metal atoms diffuse because of a potential.
Influence of Temperature on Magnetic Behavior
There is no perfect material?
Electromigration
Iron-Silicon Alloy in Transformer Cores
28. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Incoherent
Incident Light
Work Hardening
Ductile-to-Brittle Transition
29. - 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
Relative Permeability
Ductile Fracture
30. Increase temperature - increase in interatomic separation - thermal expansion
Transparent
Thermal Expansion: Asymmetric curve
Etching
Thermal Shock Resistance
31. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
32. Becomes harder (more strain) to stretch (elongate)
Superconductivity
Stress Intensity Factor
Work Hardening
4 Types of Magnetism
33. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Transparent
Electromigration
What do magnetic moments arise from?
Ductile-to-Brittle Transition
34. Wet: isotropic - under cut Dry: ansiotropic - directional
Why do ceramics have larger bonding energy?
Linewidth
There is no perfect material?
Etching
35. 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
Intrinsic Semiconductors
Oxidation
Relative Permeability
36. 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
Thermal Stresses
Domains in Ferromagnetic & Ferrimagnetic Materials
Refraction
Force Decomposition
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.
Rockwell
Translucent
Modulus of Rupture (MOR)
Etching
38. Without passing a current a continually varying magnetic field will cause a current to flow
Reflectance of Non-Metals
Response to a Magnetic Field
Shear and Tensile Stress
Magnetic Storage
39. # of thermally generated electrons = # of holes (broken bonds)
Thermal Stresses
Intrinsic Semiconductors
Sparkle of Diamonds
Paramagnetic Materials
40. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
True Strain
Why materials fail in service
Holloman Equation
Stress Intensity values
41. Ohms Law: voltage drop = current * resistance
Electrical Conduction
Transgranular Fracture
Metals: Resistivity vs. T - Impurities
M is known as what?
42. Elastic means reversible! This is not a permanent deformation.
Relative Permeability
Elastic Deformation
Insulators
Diamagnetic Materials
43. If a material has ________ - then the field generated by those moments must be added to the induced field.
Internal magnetic moments
Dependence of Heat Capacity on Temperature
Magnetic Storage
IC Devices: P-N Rectifying Junction
44. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Coherent
Why do ceramics have larger bonding energy?
Impact energy
HB (Brinell Hardness)
45. 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.
Magnetic Storage Media Types
Shear and Tensile Stress
Sparkle of Diamonds
LASER
46. A measure of the ease with which a B field can be induced inside a material.
Impact - Toughness
Internal magnetic moments
Relative Permeability
Why fracture surfaces have faceted texture
47. Stress concentration at a crack tips
Griffith Crack Model
Scattering
Thermal Shock Resistance
Valence band
48. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Griffith Crack Model
Lithography
Why materials fail in service
Oxidation
49. Undergo extensive plastic deformation prior to failure.
Two kinds of Reflection
Electrical Conduction
Ductile Materials
Brittle Materials
50. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Scattering
Thermal Shock Resistance
Generation of a Magnetic Field - Within a Solid Material
Internal magnetic moments