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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. 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.
M is known as what?
Diamagnetic Materials
Brittle Fracture
Etching
2. 1. Insulators: Higher energy states NOT ACCESSIBLE due to gap 2. Semiconductors: Higher energy states separated by a smaller gap.
Thermal Expansion: Symmetric curve
Why fracture surfaces have faceted texture
Relative Permeability
Energy States: Insulators and Semiconductors
3. 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
Impact energy
Thermal Expansion: Asymmetric curve
Iron-Silicon Alloy in Transformer Cores
Thermal Conductivity
4. These materials are "attracted" to magnetic fields.
Heat Capacity from an Atomic Prospective
Thermal Expansion: Symmetric curve
Paramagnetic Materials
Translucent
5. 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
Heat Capacity
Thermal Expansion: Symmetric curve
How an LCD works
Refraction
6. 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.
Heat Capacity
Metallization
Refraction
Paramagnetic Materials
7. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Oxidation
Etching
Thermal Shock Resistance
Metals: Resistivity vs. T - Impurities
8. Flaws and Defects - They concentrate stress locally to levels high enough to rupture bonds.
Intrinsic Semiconductors
Large Hardness
Fourier's Law
Why materials fail in service
9. Different orientation of cleavage planes in grains.
Film Deposition
Metals: Resistivity vs. T - Impurities
Hysteresis and Permanent Magnetization
Why fracture surfaces have faceted texture
10. Becomes harder (more strain) to stretch (elongate)
Magnetic Storage
Work Hardening
Response to a Magnetic Field
Liquid Crystal Displays (LCD's)
11. Undergo little or no plastic deformation.
Incoherent
Shear and Tensile Stress
Refraction
Brittle Materials
12. Growing interconnections to connect devices -Low electrical resistance - good adhesion to dielectric insulators.
Not severe
Coefficient of Thermal Expansion
Metallization
How an LCD works
13. ...occurs in bcc metals but not in fcc metals.
4 Types of Magnetism
Electrical Conduction
Where does DBTT occur?
Hard Magnetic Materials
14. Increase temperature - no increase in interatomic separation - no thermal expansion
Domains in Ferromagnetic & Ferrimagnetic Materials
Ductile-to-Brittle Transition
Thermal Expansion: Symmetric curve
Refraction
15. - 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
Luminescence
Griffith Crack Model
Stress Intensity values
Stages of Failure: Ductile Fracture
16. 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.
Generation of a Magnetic Field - Vacuum
Heat Capacity
Paramagnetic Materials
Shear and Tensile Stress
17. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Modulus of Rupture (MOR)
Heat Capacity
Reflectance of Non-Metals
Elastic Deformation
18. Increase temperature - increase in interatomic separation - thermal expansion
Thermal Expansion: Asymmetric curve
Conduction & Electron Transport
Slip Bands
Valence band
19. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Intrinsic Semiconductors
Sparkle of Diamonds
Holloman Equation
True Strain
20. 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
Brittle Fracture
The Transistor
Hysteresis and Permanent Magnetization
Why materials fail in service
21. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Thermal expansion
Pure Semiconductors: Conductivity vs. T
Hysteresis and Permanent Magnetization
HB (Brinell Hardness)
22. Allows you to calculate what happened G=F' x cos(lambda) - F=F' x cos(phi)
Response to a Magnetic Field
Force Decomposition
Elastic Deformation
Meissner Effect
23. 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
Specific Heat
Domains in Ferromagnetic & Ferrimagnetic Materials
Opaque
Refraction
24. Because of ionic & covalent-type bonding.
Lithography
Rockwell
Why do ceramics have larger bonding energy?
Opacifiers
25. A measure of the ease with which a B field can be induced inside a material.
Relative Permeability
Stages of Failure: Ductile Fracture
Liquid Crystal Displays (LCD's)
Yield and Reliability
26. Ohms Law: voltage drop = current * resistance
4 Types of Magnetism
Electrical Conduction
Film Deposition
Where does DBTT occur?
27. 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.
Heat Capacity from an Atomic Prospective
Scattering
Meissner Effect
Thermal Conductivity
28. 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.
Extrinsic Semiconductors
Insulators
Oxidation
Color
29. Emitted light is in phase
Luminescence examples
Soft Magnetic Materials
Coherent
Refraction
30. The ability of a material to be rapidly cooled and not fracture
Metals: Resistivity vs. T - Impurities
Thermal Shock Resistance
Plastic Deformation (Metals)
Stress Intensity Factor
31. Elastic means reversible! This is not a permanent deformation.
Griffith Crack Model
Superconductivity
Paramagnetic Materials
Elastic Deformation
32. 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.
LASER
Slip Bands
Hardness
Electrical Conduction
33. A high index of refraction (n value) allows for multiple internal reactions.
Linewidth
Translucent
Sparkle of Diamonds
Ductile-to-Brittle Transition
34. 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
Thermal Conductivity
Thermal Shock Resistance
How to gage the extent of plastic deformation
True Strain
35. Light Amplification by Stimulated Emission of Radiation
Elastic Deformation
LASER
Brittle Ceramics
Extrinsic Semiconductors
36. Diffuse image
Electrical Conduction
Translucent
Where does DBTT occur?
True Stress
37. Occur when lots of dislocations move.
Where does DBTT occur?
Slip Bands
Reflectance of Non-Metals
Reflection of Light for Metals
38. 1. Tensile (opening) 2. Sliding 3. Tearing
Luminescence
LASER
The three modes of crack surface displacement
Brittle Fracture
39. # of thermally generated electrons = # of holes (broken bonds)
Intrinsic Semiconductors
There is no perfect material?
Generation of a Magnetic Field - Within a Solid Material
Luminescence examples
40. 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
Thermal Conductivity
Elastic Deformation
Domains in Ferromagnetic & Ferrimagnetic Materials
Critical Properties of Superconductive Materials
41. With Increasing temperature - the saturation magnetization diminishes gradually and then abruptly drops to zero at Curie Temperature - Tc.
Thermal Conductivity
The Transistor
Thermal Shock Resistance
Influence of Temperature on Magnetic Behavior
42. Stress concentration at a crack tips
Sparkle of Diamonds
Shear and Tensile Stress
Griffith Crack Model
Generation of a Magnetic Field - Within a Solid Material
43. Undergo extensive plastic deformation prior to failure.
Why do ceramics have larger bonding energy?
Intergranular Fracture
The three modes of crack surface displacement
Ductile Materials
44. 1. Hard disk drives (granular/perpendicular media) 2. Recording tape (particulate media)
Magnetic Storage Media Types
High impact energy
Meissner Effect
Reflection of Light for Metals
45. Specular: light reflecting off a mirror (average) - Diffuse: light reflecting off a white wall (local)
Soft Magnetic Materials
Two kinds of Reflection
Generation of a Magnetic Field - Within a Solid Material
Intrinsic Semiconductors
46. These are liquid crystal polymers- not your normal "crystal" -Rigid - rod shaped molecules are aligned even in liquid form.
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47. Impurities added to the semiconductor that contribute to excess electrons or holes. Doping = intentional impurities.
Extrinsic Semiconductors
Dependence of Heat Capacity on Temperature
Hysteresis and Permanent Magnetization
Refraction
48. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Generation of a Magnetic Field - Vacuum
Color
Dependence of Heat Capacity on Temperature
Stress Intensity values
49. Occur due to: restrained thermal expansion/contraction -temperature gradients that lead to differential dimensional changes sigma = Thermal Stress
Thermal Stresses
LASER
Two kinds of Reflection
Ductile-to-Brittle Transition
50. Without passing a current a continually varying magnetic field will cause a current to flow
Response to a Magnetic Field
Opacity
Ductile-to-Brittle Transition
Paramagnetic Materials