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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. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Engineering Fracture Performance
Incident Light
Conduction & Electron Transport
Coherent
2. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
How to gage the extent of plastic deformation
Two ways to measure heat capacity
Critical Properties of Superconductive Materials
Thermal Stresses
3. - 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
Etching
Linewidth
Metallization
Stress Intensity values
4. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Metals: Resistivity vs. T - Impurities
Rockwell
Etching
Energy States: Insulators and Semiconductors
5. 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
Yield and Reliability
Modulus of Rupture (MOR)
Oxidation
Shear and Tensile Stress
6. Increase temperature - increase in interatomic separation - thermal expansion
Modulus of Rupture (MOR)
Hysteresis and Permanent Magnetization
Coherent
Thermal Expansion: Asymmetric curve
7. As the applied field (H) increases the magnetic domains change shape and size by movement of domain boundaries.
Generation of a Magnetic Field - Vacuum
Hysteresis and Permanent Magnetization
IC Devices: P-N Rectifying Junction
Domains in Ferromagnetic & Ferrimagnetic Materials
8. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Specific Heat
Diamagnetic Materials
There is no perfect material?
Hard Magnetic Materials
9. Ability to transmit a clear image - The image is clear.
Transparent
Insulators
Heat Capacity
Paramagnetic Materials
10. They are used to assess properties of ceramics & glasses.
Liquid Crystal Displays (LCD's)
Bending tests
Heat Capacity from an Atomic Prospective
Fourier's Law
11. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Generation of a Magnetic Field - Within a Solid Material
Etching
Intergranular Fracture
Griffith Crack Model
12. 1. Impose a compressive surface stress (to suppress surface cracks from growing) - Method 1: shot peening - Method 2: carburizing 2.Remove stress concentrators.
True Stress
Diamagnetic Materials
To improve fatigue life
Insulators
13. Undergo extensive plastic deformation prior to failure.
Modulus of Rupture (MOR)
Impact - Toughness
Ductile Materials
Thermal Stresses
14. - 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
Opacifiers
Opacity
Two ways to measure heat capacity
Luminescence
15. There is always some statistical distribution of flaws or defects.
Reflectance of Non-Metals
Internal magnetic moments
Work Hardening
There is no perfect material?
16. Found in 26 metals and hundreds of alloys & compounds - Tc= critical temperature = termperature below which material is superconductive.
Modulus of Rupture (MOR)
Thermal Expansion: Symmetric curve
Brittle Materials
Superconductivity
17. (sigma)=F/Ai (rho)=(rho)'(1+(epsilon))
High impact energy
True Stress
Why fracture surfaces have faceted texture
Hysteresis and Permanent Magnetization
18. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
IC Devices: P-N Rectifying Junction
Meissner Effect
Holloman Equation
Charpy or Izod test
19. 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
4 Types of Magnetism
Two kinds of Reflection
Intrinsic Semiconductors
Why fracture surfaces have faceted texture
20. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Magnetic Storage Media Types
Extrinsic Semiconductors
Domains in Ferromagnetic & Ferrimagnetic Materials
Coefficient of Thermal Expansion
21. High toughness; material resists crack propagation.
High impact energy
Incoherent
Ductile-to-Brittle Transition
Insulators
22. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Refraction
Oxidation
Extrinsic Semiconductors
Fourier's Law
23. Ohms Law: voltage drop = current * resistance
Critical Properties of Superconductive Materials
Electrical Conduction
Coefficient of Thermal Expansion
Internal magnetic moments
24. Stress concentration at a crack tips
Response to a Magnetic Field
Griffith Crack Model
Color
Influence of Temperature on Magnetic Behavior
25. heat flux = -(thermal conductivity)(temperature gradient) - Defines heat transfer by CONDUCTION
26. 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
Why fracture surfaces have faceted texture
Domains in Ferromagnetic & Ferrimagnetic Materials
Brittle Materials
Magnetic Storage
27. 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.
There is no perfect material?
Brittle Ceramics
Oxidation
Heat Capacity from an Atomic Prospective
28. 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
Insulators
Impact - Toughness
Scattering
Brittle Ceramics
29. 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.
Plastic Deformation (Metals)
Internal magnetic moments
Hard Magnetic Materials
High impact energy
30. 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
Color
Reflectance of Non-Metals
High impact energy
31. Specific heat = energy input/(mass*temperature change)
Thermal Expansion: Symmetric curve
Specific Heat
True Stress
Lithography
32. Width of smallest feature obtainable on Si surface
Linewidth
Heat Capacity
Electrical Conduction
Why fracture surfaces have faceted texture
33. Different orientation of cleavage planes in grains.
Why fracture surfaces have faceted texture
Thermal expansion
Extrinsic Semiconductors
Incoherent
34. Sigma=ln(li/lo)
True Strain
LASER
Generation of a Magnetic Field - Vacuum
Paramagnetic Materials
35. Allows flow of electrons in one direction only (useful to convert alternating current to direct current) - Result: no net current flow
Sparkle of Diamonds
Thermal Expansion: Asymmetric curve
Ductile Fracture
IC Devices: P-N Rectifying Junction
36. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Force Decomposition
To improve fatigue life
Refraction
Brittle Ceramics
37. A measure of the ease with which a B field can be induced inside a material.
Thermal Expansion: Symmetric curve
LASER
Relative Permeability
Plastic Deformation (Metals)
38. Is analogous to toughness.
HB (Brinell Hardness)
Charpy or Izod test
Reflection of Light for Metals
Impact energy
39. Cracks propagate along grain boundaries.
M is known as what?
Heat Capacity from an Atomic Prospective
Intergranular Fracture
Metallization
40. Diffuse image
Griffith Crack Model
HB (Brinell Hardness)
Ductile Fracture
Translucent
41. 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.
Refraction
Opaque
Influence of Temperature on Magnetic Behavior
To improve fatigue life
42. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Magnetic Storage
Thermal Conductivity
Insulators
Modulus of Rupture (MOR)
43. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
44. No appreciable plastic deformation. The crack propagates very fast; nearly perpendicular to applied stress. Cracks often propagate along specific crystal planes or boundaries.
Hardness
Brittle Fracture
Valence band
Meissner Effect
45. Light Amplification by Stimulated Emission of Radiation
LASER
IC Devices: P-N Rectifying Junction
Sparkle of Diamonds
Incoherent
46. Emitted light is in phase
Coherent
Domains in Ferromagnetic & Ferrimagnetic Materials
High impact energy
Transgranular Fracture
47. Dimples on fracture surface correspond to microcavities that initiate crack formation.
Generation of a Magnetic Field - Vacuum
LASER
Ductile Fracture
Why do ceramics have larger bonding energy?
48. 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
Holloman Equation
Refraction
Why do ceramics have larger bonding energy?
Griffith Crack Model
49. 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
Where does DBTT occur?
Paramagnetic Materials
How an LCD works
50. A high index of refraction (n value) allows for multiple internal reactions.
Generation of a Magnetic Field - Within a Solid Material
Griffith Crack Model
LASER
Sparkle of Diamonds