SUBJECTS
|
BROWSE
|
CAREER CENTER
|
POPULAR
|
JOIN
|
LOGIN
Business Skills
|
Soft Skills
|
Basic Literacy
|
Certifications
About
|
Help
|
Privacy
|
Terms
|
Email
Search
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. 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
Refraction
Rockwell
Superconductivity
Stages of Failure: Ductile Fracture
2. Resistance to plastic deformation of cracking in compression - and better wear properties.
Plastic Deformation (Metals)
Large Hardness
There is no perfect material?
Diamagnetic Materials
3. 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
Superconductivity
Brittle Fracture
Reflectance of Non-Metals
4. Superconductors expel magnetic fields - This is why a superconductor will float above a magnet.
Linewidth
How to gage the extent of plastic deformation
Meissner Effect
Metallization
5. 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.
Impact energy
Yield and Reliability
IC Devices: P-N Rectifying Junction
Scattering
6. Second phase particles with n > glass.
Pure Semiconductors: Conductivity vs. T
Opacifiers
Coherent
Sparkle of Diamonds
7. Light Amplification by Stimulated Emission of Radiation
Reflection of Light for Metals
4 Types of Magnetism
LASER
Heat Capacity from an Atomic Prospective
8. 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
Dependence of Heat Capacity on Temperature
Energy States: Insulators and Semiconductors
Transparent
9. 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
Brittle Ceramics
Conduction & Electron Transport
Engineering Fracture Performance
10. 1. Electron motions 2. The spins on electrons - Net atomic magnetic moment: sum of moments from all electrons.
Intergranular Fracture
Linewidth
Not severe
What do magnetic moments arise from?
11. - A magnetic field is induced in the material B= Magnetic Induction (tesla) inside the material mu= permeability of a solid
Pure Semiconductors: Conductivity vs. T
Intrinsic Semiconductors
Generation of a Magnetic Field - Within a Solid Material
Rockwell
12. Diffuse image
Translucent
Brittle Fracture
Dependence of Heat Capacity on Temperature
Work Hardening
13. Degree of opacity depends on size and number of particles - Opacity of metals is the result of conduction electrons absorbing photons in the visible range.
Luminescence
Opacity
Transparent
Elastic Deformation
14. 1. Data for Pure Silicon - electrical conductivity increases with T - opposite to metals
4 Types of Magnetism
Pure Semiconductors: Conductivity vs. T
Why fracture surfaces have faceted texture
Opaque
15. Cracks pass through grains - often along specific crystal planes.
Thermal Conductivity
Transgranular Fracture
How an LCD works
Critical Properties of Superconductive Materials
16. Cp: Heat capacity at constant pressure Cv: Heat capacity at constant volume.
Two ways to measure heat capacity
Heat Capacity
Transparent
Electromigration
17. These materials are relatively unaffected by magnetic fields.
Magnetic Storage
Brittle Materials
Soft Magnetic Materials
Diamagnetic Materials
18. Ability to transmit a clear image - The image is clear.
Work Hardening
Translucent
Transparent
Response to a Magnetic Field
19. Large coercivities - Used for permanent magnets - Add particles/voids to inhibit domain wall motion - Example: tungsten steel
Liquid Crystal Displays (LCD's)
Why fracture surfaces have faceted texture
Incoherent
Hard Magnetic Materials
20. Typical loading conditions are _____ enough to break all inter-atomic bonds
Rockwell
Internal magnetic moments
Not severe
Coefficient of Thermal Expansion
21. To build a device - various thin metal or insulating films are grown on top of each other - Evaporation - MBE - Sputtering - CVD (ALD)
Film Deposition
Elastic Deformation
Ductile Fracture
Work Hardening
22. Cracks propagate along grain boundaries.
Thermal Conductivity
Linewidth
Intergranular Fracture
Lithography
23. 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
Ductile-to-Brittle Transition
4 Types of Magnetism
Electrical Conduction
Etching
24. Increase temperature - no increase in interatomic separation - no thermal expansion
Two kinds of Reflection
Luminescence
Thermal Expansion: Symmetric curve
Etching
25. Is reflected - absorbed - scattered - and/or transmitted: Io=It+Ia+Ir+Is
Incident Light
Hard Magnetic Materials
Refraction
Thermal Expansion: Symmetric curve
26. (sigma)=K(sigma)^n . K = strength coefficient - n = work hardening rate or strain hardening exponent. Large n value increases strength and hardness.
Thermal Expansion: Symmetric curve
Holloman Equation
The three modes of crack surface displacement
The Transistor
27. Becomes harder (more strain) to stretch (elongate)
Transparent
Stress Intensity Factor
Work Hardening
Two kinds of Reflection
28. This strength parameter is similar in magnitude to a tensile strength. Fracture occurs along the outermost sample edge - which is under a tensile load.
Etching
Superconductivity
Thermal Expansion: Asymmetric curve
Modulus of Rupture (MOR)
29. 1. Fluorescent Lamp - tungstate or silicate coating on inside of tube emits white light due to UV light generated inside the tube. 2. TV screen - emits light as electron beam is scanned back and forth.
Luminescence examples
Griffith Crack Model
Thermal Expansion: Symmetric curve
Yield and Reliability
30. High toughness; material resists crack propagation.
To improve fatigue life
True Strain
Superconductivity
High impact energy
31. 1. General yielding occurs if flaw size a < a(critical) 2. Catastrophic fast fracture occurs if flaw size a > a(critical)
Oxidation
Engineering Fracture Performance
Hysteresis and Permanent Magnetization
Energy States: Insulators and Semiconductors
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)
Why materials fail in service
Rockwell
Yield and Reliability
Refraction
33. 1. Imperfections increase resistivity - grain boundaries - dislocations - impurity atoms - vacancies 2. Resistivity - increases with temperature - wt% impurity - and %CW
Metals: Resistivity vs. T - Impurities
Incoherent
Diamagnetic Materials
Brittle Ceramics
34. Dramatic change in impact energy is associated with a change in fracture mode from brittle to ductile.
Stages of Failure: Ductile Fracture
Pure Semiconductors: Conductivity vs. T
Ductile-to-Brittle Transition
Coherent
35. 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.
Impact - Toughness
Magnetic Storage Media Types
Shear and Tensile Stress
Influence of Temperature on Magnetic Behavior
36. A high index of refraction (n value) allows for multiple internal reactions.
Brittle Materials
4 Types of Magnetism
Sparkle of Diamonds
Intergranular Fracture
37. Process by which geometric patterns are transferred from a mask (reticle) to a surface of a chip to form the device.
Lithography
Ductile-to-Brittle Transition
Coefficient of Thermal Expansion
Iron-Silicon Alloy in Transformer Cores
38. 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
Opacity
Thermal Conductivity
Why do ceramics have larger bonding energy?
HB (Brinell Hardness)
39. Another optical property - Depends on the wavelength of the visible spectrum.
Insulators
Griffith Crack Model
Brittle Ceramics
Color
40. 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.
Generation of a Magnetic Field - Vacuum
Plastic Deformation (Metals)
Energy States: Insulators and Semiconductors
HB (Brinell Hardness)
41. 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.
Where does DBTT occur?
Incident Light
Brittle Ceramics
True Stress
42. Heat capacity.....- increases with temperature -for solids it reaches a limiting value of 3R
Ductile-to-Brittle Transition
Fourier's Law
Dependence of Heat Capacity on Temperature
Extrinsic Semiconductors
43. Measures Hardness 1. psia = 500 x HB 2. MPa = 3.45 x HB
Incident Light
HB (Brinell Hardness)
Film Deposition
High impact energy
44. 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
Reflection of Light for Metals
Brittle Materials
Incoherent
Thermal Expansion: Asymmetric curve
45. 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
IC Devices: P-N Rectifying Junction
Hysteresis and Permanent Magnetization
Color
True Stress
46. -> fluorescent light - electron transitions occur randomly - light waves are out of phase with each other.
Incoherent
Holloman Equation
Thermal Stresses
Oxidation
47. The ability of a material to be rapidly cooled and not fracture
Generation of a Magnetic Field - Vacuum
4 Types of Magnetism
Thermal Shock Resistance
Linewidth
48. Elastic means reversible! This is not a permanent deformation.
Impact - Toughness
Elastic Deformation
LASER
Metallization
49. Because of ionic & covalent-type bonding.
Meissner Effect
Slip Bands
Why do ceramics have larger bonding energy?
Luminescence
50. There is always some statistical distribution of flaws or defects.
Refraction
Heat Capacity
Metals: Resistivity vs. T - Impurities
There is no perfect material?